Sentence Correction

The strand fills the water during the rainy season that the peat then holds and keeps it humid, all of which creates conditions enabling trees to grow.

A. enabling trees to grow

B. for the trees to grow

C. for growing trees

D. that enable the trees to grow

E. that the trees can grow

OA - D

Any help explaining the right answer and its associated grammar rule.

Also any explanation on the correct usage of "ing" form (in this case enabling) would be much appreciated

Thank you