Which best describes how the fossil record supports the theory of evolution?
a. The fossil record shows exactly how all species have evolved.
b. The fossil record refutes Darwin's theories.
c. The fossil record cannot accurately be aged.
d. The fossil record reveals intermediates that link different species.

I'd go with option D. Though we cannot see exactly what has changed, as changes are often quite gradual, we can observe intermediates that link different species together.

The correct answer will be the d. The fossil record reveals intermediates that link different species. It best describes how the fossil record supports the theory of evolution.  By dating fossils and comparing them to other fossils, we can piece together the general path that evolution took, and determine when certain features appeared.