"Theory of" is not correct in (A). "Theory that" is preferred.
I guess it would be easier to explain this question with all the answer
choices.
wrote:
(A) supporting the theory of global forest fires ignited by a meteorite impact that
(B) supporting the theory that global forest fires ignited by a meteorite impact
(C) that supports the theory of global forest fires that were ignited by a meteorite impact and that
(D) in support of the theory that global forest fires were ignited by a meteorite impact and that
(E) of support for the theory of a meteorite impact that ignited global forest fires and
Using the 2/3 principle, you can eliminate A, C and E.
D changes the meaning.