You are presented with the quiz "What may vary in size as well as shape, but all are very small?" But you don't know the answer, so you turn to your teacher to ask for hints. He says that "cells vary in size as well as shape, but all cells are very small" and "basic unit of the plant body is the cell". So, what's the best answer to the question?

Select from the following.
(1). keeping food fresh for long periods of time.
(2). disease-causing microorganisms.
(3). A solid geometric shape.
(4). Unequal radiation absorption.
(5). Small countries..
(6). Shapewear..
(7). A water well..
(8). Basic units of the plant body..
The answer is:
(8).