The correct answer is D. Cell
Explanation:
In biology, all living organisms are composed of basic units called cells, this includes the simple organisms that are composed by one or a few cells to complex organisms that are composed of multiple cells that create tissues and organs. Due to this, cells are considered the basic unit in all living things or organisms, which means life cannot exist without cells. Additionally, cells are complex structures with multiple functions such as reproduction, growth, synthesis of substances, etc. therefore, cells are also basic units of function. Thus, the term that defines the basic unit of structure and function in all living things are cells.
