Cells are small. Cells are alive. Cells move quickly. Cells have an electrical charge.
I gave my students this multiple choice question: With the development of the microscope, scientists were able to see cells for the first time. Why was it difficult to view cells without a microscope?

Only one answer is correct among these 4 choices:
- Cells are small.
- Cells are alive.
- Cells move quickly.
- Cells have an electrical charge.

Could you tell me which one is correct?

Cells are small.