The structure of endoplasmic reticulum is not visible under a light microscope,but it can be seen with an electron microscope because

A) electron beams have more energy than light beams.
B) electron microscopes focus light with magnets.
C) electron microscopes have more resolving power than light microscopes.
D) electrons have such high energy that they pass through biological samples.
E) living cells can be observed under the electron microscope.