Answer:
The answer is letter A.
Explanation:
During anaerobic respiration, lactate levels increase when muscles cells need more energy, however muscles cells eventually fatigue, thus athletes should modify their activities to increase aerobic respiration.
In energy processing systems electronic carrier molecules transfer electrons from one part to other part of energy processing system. This provides the necessary energy and reduces power to carry out chemical reactions. They are necessary for aerobic cellular respiration and photosynthesis.