Daniel Hillel developed drip irrigation   techniques. The techniques make farming possible in places where there is not enough water. Because of this, he won this year's World Food Prize. Hillel is using the techniques in his orchards   near his home in Israel. Irrigating drop by drop -- called drip irrigation -- has changed agriculture by greatly reducing the amount of water needed. Farmers now rely on it in places from Spain, to Africa, to America. "We in California grow about 50 percent of the fruits and vegetables of the continental United States," says Jan Hopmans from University of California at Davis. "And these drip irrigation techniques make it possible." Hillel got his start in dry land farming in Israel's Negev Desert in the 1950s. "The key was making good use of water," he says. "There's much land. Water is limited." These farmers did not have the advantage of running irrigation water through channels   to their crops. So Hillel and others gave plants just what they needed and just where they needed it. "The idea is to use water little by little," Hillel says. It worked so well that Hillel was soon traveling around the world, showing others how to do it. Experts say drip irrigation's importance is growing, as climate change and rising population make water supplies become few in many parts of the world. "This is where water use, climate change and crop production all meet at one point," Hillel says. "And this has been really the essence   of my career." A career whose importance can be measured drop by drop. The writer considers Daniel Hillel's career to be  _  .
worthy of respect worthy of understanding brief hard
Question: Daniel Hillel developed drip irrigation   techniques. The techniques make farming possible in places where there is not enough water. Because of this, he won this year's World Food Prize. Hillel is using the techniques in his orchards   near his home in Israel. Irrigating drop by drop -- called drip irrigation -- has changed agriculture by greatly reducing the amount of water needed. Farmers now rely on it in places from Spain, to Africa, to America. "We in California grow about 50 percent of the fruits and vegetables of the continental United States," says Jan Hopmans from University of California at Davis. "And these drip irrigation techniques make it possible." Hillel got his start in dry land farming in Israel's Negev Desert in the 1950s. "The key was making good use of water," he says. "There's much land. Water is limited." These farmers did not have the advantage of running irrigation water through channels   to their crops. So Hillel and others gave plants just what they needed and just where they needed it. "The idea is to use water little by little," Hillel says. It worked so well that Hillel was soon traveling around the world, showing others how to do it. Experts say drip irrigation's importance is growing, as climate change and rising population make water supplies become few in many parts of the world. "This is where water use, climate change and crop production all meet at one point," Hillel says. "And this has been really the essence   of my career." A career whose importance can be measured drop by drop. The writer considers Daniel Hillel's career to be  _  .
A. worthy of respect
B. worthy of understanding
C. brief
D. hard
Answer: