Reading that, I believe his reason for endorsing #4 is that he made the assumption that neither of their claims relies on any evidence relied on by the other. If we assume this, I agree that #4 is the right answer, but I do not think that is a valid assumption.
Reading that, I believe his reason for endorsing #4 is that he made the assumption that neither of their claims relies on any evidence relied on by the other. If we assume this, I agree that #4 is the right answer, but I do not think that is a valid assumption.