During activities requiring aerobic endurance,

A) glycogen and glycolysis are the primary sources of reserve energy

B) oxygen debts are common.

C) most of the muscle's energy is produced in mitochondria.

D) fatigue occurs in a few minutes.

E) all of the above

C) most of the muscle's energy is produced in mitochondria.

Explanation:

The activities such as running a marathon require aerobic endurance to allow prolonged and sustained muscle contraction for a longer duration (few hours) without fatigue. These activities rely on the production of ATPs in mitochondria through the process of anaerobic cellular respiration.

The process of aerobic cellular respiration produces a large number of ATPs to sustain prolonged muscle contraction. Slow oxidative muscle fibers that contain a large amount of myoglobin and are rich in mitochondria are involved in such activities.