Store shelves are filling up with so-called "green" products promising to benefit the environment. A recent argument shows that it can be as difficult for buyers to confirm such statement as for producers to defend them. The argument concerns the GreenPlug Electricity Saver. The GreenPlug is supposed to prevent energy waste by electrical equipment whose constant -speed motors operate at less full load---as is especially true of older refrigerators. Research showed that such motors can be made to do the same work with less heat, noise, and power consumption just by lowering the voltage of the power supply.           John and Wyck Hay, started Green Technologies to apply that finding to home appliances. In  the USA, there are more than 140 million refrigerators in use, accounting for an average of 16% of  the household electric bill.  Two years of research resulted in the GreenPlug. Connecting between wall socket and refrigerator, the equipment contains a minicomputer that gives a motor full power (120 volts on average) for start-up, then reduces the power to 106 volts. Older refrigerators are the most overpowered and, thus, save the most energy with a GreenPlug. Refrigerators less than two years old are already energy-saving that a GreenPlug actually makes them waste electricity. The higher the voltage, the larger the difference a GreenPlug makes. Higher power costs shorten the payback time. The population-weighted national average is 10 cents per kilowatt-hour. But some residents in Washington State pay 1.5 cents. Some in Alaska pay 41.6 cents. Then come highly individual household differences like the number of children or refrigerator -opening age. All in all, the GreenPlug should save the average consumer $20 a year. Although the GreenPlug lowered the voltage as it was designed to do,Consumer Reports, an influential magazine, questioned how quickly---if ever---electricity savings due to the plug would repay its cost. People would be better off buying a new, high-efficiency refrigerator, the magazine advised. Consumer Reports also said that the GreenPlug didn't give a promised 25% savings worth $50 a year. The savings on the oldest model was the best at 8.6%, worth $20 a year.  Green Technologies ordered tests of the GreenPlug on up to 2,800 refrigerators through next year. The company will not put that data in stores. Instead, potential buyers will call to learn how their model of refrigerator performed.           Meanwhile, there is little evidence of consumer dissatisfaction. Sales topped 45,000 units last  month. The return rate is less than 0.2%. What do we know about the GreenPlug?
It is especially designed for old refrigerators It works well with all home appliances It can't guarantee lower electric bills It doesn't function with lower voltage
Question: Store shelves are filling up with so-called "green" products promising to benefit the environment. A recent argument shows that it can be as difficult for buyers to confirm such statement as for producers to defend them. The argument concerns the GreenPlug Electricity Saver. The GreenPlug is supposed to prevent energy waste by electrical equipment whose constant -speed motors operate at less full load---as is especially true of older refrigerators. Research showed that such motors can be made to do the same work with less heat, noise, and power consumption just by lowering the voltage of the power supply.           John and Wyck Hay, started Green Technologies to apply that finding to home appliances. In  the USA, there are more than 140 million refrigerators in use, accounting for an average of 16% of  the household electric bill.  Two years of research resulted in the GreenPlug. Connecting between wall socket and refrigerator, the equipment contains a minicomputer that gives a motor full power (120 volts on average) for start-up, then reduces the power to 106 volts. Older refrigerators are the most overpowered and, thus, save the most energy with a GreenPlug. Refrigerators less than two years old are already energy-saving that a GreenPlug actually makes them waste electricity. The higher the voltage, the larger the difference a GreenPlug makes. Higher power costs shorten the payback time. The population-weighted national average is 10 cents per kilowatt-hour. But some residents in Washington State pay 1.5 cents. Some in Alaska pay 41.6 cents. Then come highly individual household differences like the number of children or refrigerator -opening age. All in all, the GreenPlug should save the average consumer $20 a year. Although the GreenPlug lowered the voltage as it was designed to do,Consumer Reports, an influential magazine, questioned how quickly---if ever---electricity savings due to the plug would repay its cost. People would be better off buying a new, high-efficiency refrigerator, the magazine advised. Consumer Reports also said that the GreenPlug didn't give a promised 25% savings worth $50 a year. The savings on the oldest model was the best at 8.6%, worth $20 a year.  Green Technologies ordered tests of the GreenPlug on up to 2,800 refrigerators through next year. The company will not put that data in stores. Instead, potential buyers will call to learn how their model of refrigerator performed.           Meanwhile, there is little evidence of consumer dissatisfaction. Sales topped 45,000 units last  month. The return rate is less than 0.2%. What do we know about the GreenPlug?
A. It is especially designed for old refrigerators
B. It works well with all home appliances
C. It can't guarantee lower electric bills
D. It doesn't function with lower voltage
Answer: