Answer:
A.
Explanation:
As we age our metabolism tends to slow down.The basal metabolic rate decreases almost linearly with age.
Energy requirement in old people tend to get less because of less physical activity.If energy intake, on the other hand, exceeds individual energy needs, fat accumulates in the body
cell
The cell is the smallest structural and functional unit of living organisms, which can exist on its own. Therefore, it is sometimes called the building block of life. Some organisms, such as bacteria or yeast, are unicellular—consisting only of a single cell—while others, for instance, mammalians, are multicellular.
