Critical Reasoning (CR) | Re: It is clear that humans during the Upper Paleolithic period used lamps

The question stem says that each of the following contributes to the explanation of the skewed distribution of the lamps.
ie each of the options except one will explain why greater number of lamps are associated with late Paleolithic period

Only one option should not explain why the distribution of lamps is skewed.

(A) Artifacts from early in the Upper Paleolithic period are harder to identify than those that originated later in the period,
- this explains the skewed distribution as the artifacts