Final answer:
The correct answer is a. anaerobic metabolism in the muscles of the sprinter. During anaerobic training, certain enzymes involved in glycolysis, such as phosphofructokinase, are up-regulated to facilitate the faster production of ATP.
Step-by-step explanation:
The correct answer is a. anaerobic metabolism in the muscles of the sprinter. During anaerobic training, the body relies on anaerobic metabolism to generate energy. This process involves the breakdown of glucose through glycolysis, which produces ATP without the need for oxygen. As a result of anaerobic training, certain enzymes involved in glycolysis, such as phosphofructokinase, are up-regulated to facilitate the faster production of ATP.