Participal Construction

Question:

Warmer climate led to changes in the ecology of Europe, ____ the animal population and methods of hunting.

(A) affecting (B) effecting (C) having affected (D) which affect
________________________

I would choose (A), since I assume the question may be rephrased as follows:

“Warmer climate led to changes in the ecology of Europe and (thus) affected the animal population and methods of hunting.”

By using participal construction, we have the sentence as stated in the question.
Any thoughts on this? Thanks for your help.