Which statements explain what the fossil record indicates

On a floor there are several 1-4 mm elongated drops leading away from a body lying in a pool of blood. the the forward wall there is a sigzag pattern and on the walls to the right side there is a linear patter

Which would be the most useful source of evidence to support mcneill's contention?

Genetic orders can result when sister chromatids fail to separate properly during which phase is this problem most likely to occur