Q: Scientists did not actually see viruses until what was invented?


Read this paragraph and choose the correct option from the provided answers:

Scientists did not actually see viruses for the first time until the 1930s. That’s when the electron microscope was invented. The virus shown in Figure below was the first one to be seen.

 Choices:

- magnifying glass

- electronic scale

- telescope

- electron microscope


A:
electron microscope