Fat is the most efficient molecule for long-term energy storage, even compared to carbohydrates, because
a. with their numerous hydrogen atoms.
b. fats provide an abundant source of high-energy electrons fats can directly enter the electron transport chain, the phase of respiration that produces the most atp compared to carbohydrates.
c. fat produces fewer toxic by-products when it is metabolized when compacted.
d. fat occupies less volume than an equivalent amount of carbohydrate p.

d.

Explanation:

Your body uses two types of molecules for storing energy, the carbohydrates are the main type and its used for short term storage, and for immediate use by the body. And the lipids or fats, are used for long term storage in the body, because they can store more energy in the same volume than a carbohydrate.

the answer is lactic acid from anaerobic respiration. the acid in lactic acid is what creates sore and burning muscles. if you think about how acid burns that will give you a clue for questions like this.

you can have just about every answer you can think of