Read the paragraph from the introduction [paragraphs 1-3].

There are trillions of cells in the human body, and they come in different shapes and sizes. There are also hundreds of different types of body cells. Each one has a specific job it is built to do. Groups of cells of the same type make specific tissues.

What conclusion can the reader make based on this paragraph?

A
There are more cells in a human body than in a plant.
B
All cells are tissue cells.
C
Humans could not live without cells.
D
Some cells are more important than other cells.