A) Examining the upper part of the lower rock layer for evidence of a catastrophic event, such as the presence of shocked quartz, iridium, or soot particles.
Step-by-step explanation:
As the fossils are different from the above layers of the rocks than in the lower and another layer of the rocks this is due to the fact that the upper parts of the ricks are evidence of the catastrophic events as the presence of the quartz and the soot particles.
The hypotheses explains this as a major extinction event that occurred in the point of time representing between the two layers of the rocks.