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 of buildup of lactic acid in your muscles, then claim that their programs will control it. Nutritionists fine-tune athletes' diets. Even the old sexual-abstinence-before-the-race dogma is being re-evaluated under the all-seeing eye of science. But I consider all this little more than tinkering. Sports records would continue to tumble even if training methods or athletic clothing or sexual practices were exactly the same today as they were in 1896, when the first modern Olympics took place. These minor miracles are the product neither of technology nor of training but of demographic patterns that affect us all
  Question: The author believes that innovations in athletic training have the most impact on:
  
   (A) Multiple generations of humans over time
   (B) One generation of humans
   (C) An athlete from a developed nation
   (D) A single individual
  Answer:
output: One generation of humans