You are presented with the question "What is used to study viruses?" and the following answer choices: 
- rays or beams
 - Cooking
 - aqueous solution
 - energy
 - an image
 - radiation
 - radiography
 - Dilution

Now knowing that viruses are so small that they can be seen only with an electron microscope and viruses are studied by radiography and use of the electron microscope, choose the best answer.


 

       radiography  