Question

what could be a reason why a researchers inference that glaciers were never present in an area because of the absence of scratches on bedrock be an incorrect inference?
bedrock is too hard to be impacted by a glacier
water and wind erosion could have smoothed the bedrock
the occurrence of glaciers over bedrock is too rare to support the claim
erosion could have moved the bedrock from its original location

Explanation:

Water and wind erosion can remove evidence of glacial - caused scratches on bedrock. Even if glaciers were present and left scratches on the bedrock in the past, subsequent water and wind erosion could have smoothed the surface, making it seem as if glaciers were never there. The other options are less likely explanations. Bedrock can be impacted by glaciers, the occurrence of glaciers over bedrock is not too rare to make the claim invalid, and erosion moving bedrock from its original location does not directly address the lack of visible scratches as a sign of non - glaciation.

Answer:

Water and wind erosion could have smoothed the bedrock