Choose the best answer:
 
Who discovered cells, and how?
 
a. Choose the famous scientist who created his own microscope in 1665.
 
b. Cork, derived from the outer bark of a tree, was found to contain ________ cells when examined under a microscope.
 
c. While observing the cork, Robert Hooke noticed a ________ structure with little compartments; he called it a _____.