Question

what is the molecule that serves as the \fork in the road\ for aerobic respiration?
nadh
glucose
pyruvate

Explanation:

Pyruvate is the key molecule. After glycolysis, in the presence of oxygen (aerobic conditions), pyruvate enters the mitochondria and is further oxidized in the citric - acid cycle. In the absence of oxygen, it can be fermented. So it serves as a "fork in the road" for aerobic respiration.

Answer:

pyruvate