Two paleontologists, Dr Tyson and Dr. Rees, disagree over the interpre

Dr Tyson and Dr. Rees disagree over the interpretation of certain footprints

Dr. Tyson - They are clearly early hominid footprints since they show human characteristics: a squarish heel and a big toe immediately adjacent to the next toe.
Dr Rees - That is not true. If it were, hominids would have had to walk in an unexpected cross-stepping manner, by placing the left foot to the right of the right foot.

The disagreement is over which of the following:

(A) the relative significance of various aspects of the evidence

There are diff aspects of the evidence -
1. the shape and size of the footprint (squarish heel, big toe adjacent to next toe),
2. the structure of the footprint (which leads to walking in cross stepping manner)

Based on 1, Dr Tyson concludes that they are hominid footprints (he ignores 2). He feels 1 is more important.
Based on 2, Dr Rees concludes that they are not (he ignores 1). He feels 2 is more important.

The two disagree over the relative importance of the diff aspects of evidence.

(B) the assumption that early hominid footprints are distinguishable from other footprints

They don't disagree over this. Dr Rees doesn't say that one cannot distinguish the hominid's footprints. He says that it is NOT hominid's footprints so apparently he believes that one can distinguish hominid's footprints.

(C) the possibility of using the evidence of footprints to determine the gait of the creature that made those footprints

Dr Tyson does not say that 2 cannot be concluded.

(D) the assumption that evidence from one paleontologic site is enough to support a conclusion

They are both making their own conclusions based on one paleontological site only. Dy Tyson says they are hominid footprints, Dr Rees says they are not. Dr Rees does not say that evidence is not enough. He says that evidence is enough to say that they are not hominid's footprints.

(E) the likelihood that early hominids would have walked upright on two feet

Again, Dr Tyson says nothing about the way hominids walked.

Answer (A)