input: Text: The Olympic Gene Pool Why the human race keeps getting faster. By Andrew Berry ( 2,168 words; posted Thursday, July 4; to be composted Thursday, July 11 ) On May 6, 1954, at Oxford University's Iffley Road track, Roger Bannister became, by just half a second, the first man to run a mile in less than four minutes. The Holy Grail of middle-distance running was his. Forty-two years later, however, that achievement seems less significant. Four-minute miles are commonplace; the current record, held by Algerian Noureddine Morceli, is 3:44, more than 5 percent faster than Bannister's speed. What Iffley Road witnessed was just another step along the road to an ever quicker mile, part of the inexorable improvement of athletic performance that we usually take for granted, particularly when the Olympics roll around. If you stop to think about it, though, such constant progress is remarkable. After all, as biomechanical machines with a standard set of parts, humans should be subject to the same limitations we see in, say, automobiles. How come they aren't? A lot of entrepreneurs and technophiles would like us to think that the answer has to do with discoveries in the world of sports technology. A new Nike shoe is trumpeted as something that will shave at least one-thousandth of a second off your 100-meter time. Trainers measure the rate
  Question: What did the Chinese do to help dispell the idea that racial differences determined racing speed?
  
   (A) The Chinese conducted extremely effective selection events. With a billion people, they were well-positioned to find more good runners if they just looked.
   (B) They divided one thousand people into two groups. One group got only the traditional Chinese diet and health care, the other group got every modern advance and a good diet. They got faster runners from the "good care" group.
   (C) China doesn't just consist of one race, and their Olympic team members do well from all the Chinese races such as the Mongolians, Uigars, Tibetans and Mandarins.
   (D) Starting from nothing, they dramatically improved the performance of their women distance event competitors by improving their training, to rank fourth in medals won  in the Olympics of the early 1990s.
  Answer:
output: Starting from nothing, they dramatically improved the performance of their women distance event competitors by improving their training, to rank fourth in medals won  in the Olympics of the early 1990s.