I just got this question on my test, the answer is D) glycogen. All excess glucose is stored long-term in the liver and muscle cells as glycogen when animals need it for energy.
Glycogen is an energy reserve polysaccharide, which is the main source of blood glucose. Its main function is to be an unlimited energy source for the organism. As is known, glucose is necessary to produce energy in the living being and to perform all the processes that occur in an organism. Glycogen is abundantly found in the liver and in smaller amounts in the muscles.
