In muscle cells, fermentation produces
a. carbon dioxide, ethanol, nadh, and atp
b. carbon dioxide, ethanol, and nad+
c. pyruvate
d. lactate, nadh, and atp
e. lactate and nad+

The correct answer is E. Lactate and NAD+

Explanation:

Fermentation occurs in anaerobic condition and in humans, most of the energy is provided by aerobic respiration but when the body needs a lot of energy in a very quick time like in sprinting then muscles use lactic acid fermentation to gain energy.

After the consumption of all stored ATP during intense work, our body starts lactic acid fermentation to gain ATP. In lactic acid fermentation, the pyruvate molecule that was produced during glycolysis is converted into lactate molecule. In this process, NADH is oxidized to NAD+.  

Therefore in lactic acid fermentation lactate and NAD+ are produced. So the correct answer is E.

after a the power stroke, adp is released, but the cross-bridge formed is still in place. atp then binds to myosin, moving the myosin to its high-energy state, releasing the myosin head from the actin active site.

i believe your answer would be c.. : )