You are presented with the quiz "To make very small objects appear bigger, one can use what instead of light for illumination?" 

But you don't know the answer, so you turn to your teacher to ask for hints. He says that "an electron microscope is used for seeing very small objects by making them appear bigger" and "electron microscopes use a beam of electrons as their source of illumination". 

So, what's the best answer to the question?


 

  electron beam         