What chemical process allows cells to be nourished and perform activities?

Metabolism is the correct choice because it encompasses all the biochemical processes that occur within a cell, allowing it to convert nutrients into energy and build the necessary molecules for sustenance and function. It involves a series of reactions that facilitate the transformation of energy and matter, enabling cells to grow, reproduce, maintain their structures, and respond to their environments.

While photosynthesis is the process by which green plants and some other organisms convert light energy into chemical energy, it is not relevant for animal cells, which do not perform photosynthesis. Respiration does refer to the process of producing energy from nutrients, but it is a specific aspect of metabolism that focuses on how cells use oxygen to break down sugar and release energy. Digestion, on the other hand, is the process of breaking down food into smaller components that can be absorbed by the body, but it occurs outside the cells and is part of the larger digestive system rather than the cellular metabolism itself. Therefore, metabolism is the most comprehensive term that accurately describes the chemical processes allowing cells to be nourished and perform activities.