Question

the basic structural and functional units of the body are ______.
organs
cells
tissues
body systems

Explanation:

In biology (a subfield of Natural Science), the cell is defined as the basic structural and functional unit of all living organisms. Organs are made of tissues, tissues are made of cells, and body systems are groups of organs. So the correct answer is cells.

Answer:

B. cells (assuming the options are labeled as A. organs, B. cells, C. tissues, D. body systems; if the original labels differ, adjust accordingly, but based on the content, the correct option is the one with "cells")