prefix = st1 /San Francisco is going to do what many other cities have already done --- provide free bicycles to the public. The mayor of San Franciscosupports the bicycle program. He wants to improve the terrible traffic problems in the city. At first, 40 to 60 bikes will be available only to city workers. People will give their old bikes to the city to use in the program. If this program is successful, one day more than 1000 bicycles will be available. Everyone, not just city workers, will be able to use these bicycles. People in Fresno,Californiaalready have a free bicycle program. In fact, this idea began inAmsterdamover 40 years ago. These programs encourage citizens to get out of their cars and onto pollution-free bikes. Fresno's Yellow Bike Program puts about fast bicycles around the city. The bikes are painted bright yellow so people know they can take them. When people take a yellow bike, they can ride to work or to shopping areas, and then leave the bike for the next rider. Some people worry that the free bikes will be stolen. However, theft hasn't been a problem in other free-bike cities. While most people think the bike program is a good idea, only a few say they will use it. "I will still drive my car," says Joanna Greene. "San Franciscohas a lot of hills. My office is at the top of Potrero Hill. I don't think _ . And, wouldn't I have to carry a helmet with me all the time?" Phil Chung agrees, "There is too much traffic. Riding a bicycle can be dangerous. There are not very many bike lanes ." He continues, "Plus, it's too cold in the winter. And what if you ride a bike to work, and then there isn't one to ride home?" Program leaders know there will be problems. But they think it's worth trying. "It's not the solution for everyone," states Sylvia Pass. "But if just one hundred people use it every day, that's one hundred cars that aren't on the streets, one hundred parking spaces that aren't used. I think it's a great beginning." San Franciscoprovides bicycles to the public because   _  .
there are many bikes available many people get tired of driving cars many other cities have already done so the traffic problems are terrible
Question: prefix = st1 /San Francisco is going to do what many other cities have already done --- provide free bicycles to the public. The mayor of San Franciscosupports the bicycle program. He wants to improve the terrible traffic problems in the city. At first, 40 to 60 bikes will be available only to city workers. People will give their old bikes to the city to use in the program. If this program is successful, one day more than 1000 bicycles will be available. Everyone, not just city workers, will be able to use these bicycles. People in Fresno,Californiaalready have a free bicycle program. In fact, this idea began inAmsterdamover 40 years ago. These programs encourage citizens to get out of their cars and onto pollution-free bikes. Fresno's Yellow Bike Program puts about fast bicycles around the city. The bikes are painted bright yellow so people know they can take them. When people take a yellow bike, they can ride to work or to shopping areas, and then leave the bike for the next rider. Some people worry that the free bikes will be stolen. However, theft hasn't been a problem in other free-bike cities. While most people think the bike program is a good idea, only a few say they will use it. "I will still drive my car," says Joanna Greene. "San Franciscohas a lot of hills. My office is at the top of Potrero Hill. I don't think _ . And, wouldn't I have to carry a helmet with me all the time?" Phil Chung agrees, "There is too much traffic. Riding a bicycle can be dangerous. There are not very many bike lanes ." He continues, "Plus, it's too cold in the winter. And what if you ride a bike to work, and then there isn't one to ride home?" Program leaders know there will be problems. But they think it's worth trying. "It's not the solution for everyone," states Sylvia Pass. "But if just one hundred people use it every day, that's one hundred cars that aren't on the streets, one hundred parking spaces that aren't used. I think it's a great beginning." San Franciscoprovides bicycles to the public because   _  .
A. there are many bikes available
B. many people get tired of driving cars
C. many other cities have already done so
D. the traffic problems are terrible
Answer: