If viruses are so small that they can be seen only with an electron lens, then viruses are so small that to see them a scientist would have to use what kind of lens?

Answer choices:
- Refract it
 - refraction of light
 - an electron lens
 - an image
 - rays or beams
 - bending light rays
 - A computer
 - flashlights

 

   an electron lens       