- The correct answer is Robert Hooke.

- In 1665, Hooke was the first scientist to use the term "cell" when he observed the structure of cork under a microscope.
- He described the small, box-like compartments as "cells" because they reminded him of the small rooms, or cells, in a monastery.
- This observation laid the foundation for cell theory, making Hooke the pioneer in introducing this crucial biological term.

Reference: The Micrographia, 1665, Chapter 10