4. Cells were first seen during the 1600s, when
English scientist Robert Hooke observed cork cel
walls through a microscope that could magnify a
specimen a couple of hundred times its original
size. In the 1800s, the compound light micro-
scope, which magnifies up to a thousand times,
was developed. Electron microscopes, which can
magnify up to a million times, were invented
during the 1900s. :

Which of the following best explains why our
knowledge of cells has grown with improve-
ments in microscope technology?

A. Each time the microscope is improved, scien-
tists can see cell structures more clearly.
B. With the first microscopes, all cell structures
were clearly visible.
C. Compound light microscopes can magnify
cells up to a thousand times.
D.
Robert Hooke's microscope only allowed him
to see the largest cell structures.