Sentence Correction (SC) | Re: Elk now live almost solely in the Rocky Mountains, which

After elimination A & B remain.

A. Elk now live almost solely in the Rocky Mountains, which would make it seem that elk are mountain dwellers, while

If I ignore the modifying phrase "which would make it seem that elk are mountain dwellers", the sentence would become:

Elk now live almost solely in the Rocky Mountains while they once ranged over virtually all of the continental United States except for a small strip in the extreme Southwest.

The sentence becomes nonsensical.

B.