You are presented with the question "Cells vary in size and shape and can only be seen with what?" and the following answer choices: 
- a microscope
 - heightened senses
 - a telescope lens
 - colors
 - Solar energy
 - by indirect light
 - a good eye
 - A computer

Now knowing that cells vary in size as well as shape, but all cells are very small and bacteria are single-cell microorganisms that are so small they can only be seen with a microscope, choose the best answer.


 

 a microscope        