GMAT Sentence Correction (SC) | Re: Sleeping pills had been showing up with regularity as a

Sleeping pills had been showing up with regularity as a factor in traffic arrests, sometimes involving drivers who later claim that they have no memory of getting behind the wheel after ingesting the pills.

Error Analysis:
Usage of past perfect is not justified. You have to have another past event to relate to.

POE:

A) Sleeping pills had been showing up with regularity as a factor in traffic arrests

Usage of past perfect is not justified. You have to have another past event to relate to.