Sentence Correction

Did a search and did not see this one posted, feel free to post link if it has already been posted.

While they remove carbon dioxide from the air, conserve soil and water, and house thousands of species, forests also supply potentially valuable pharmaceuticals, and, as sources of building material and firewood, that provide employment for millions worldwide.

A. pharmaceuticals, and, as sources of building material and firewood, that provide
B. pharmaceuticals, and sources of building material and firewood, are providers of
C. pharmaceuticals and, as sources of building material and firewood that are providing
D. pharmaceuticals and sources of building material and firewood, for providing
E. pharmaceuticals and, as sources of building material and firewood, provide

I choose D which was wrong.
OA is E

Any assistance is appreciated.