Answer:
E.
Explanation:
(A) focuses on the wrong argument ---it's focusing on whether this trade actually existed, by-passing the argument by analogy.
(B) irrelevant
(C) irrelevant
(D) this just changes the nature of what counts as evidence in the analogous argument, but it doesn't demonstrate fundamentally why the Yeti-to-trade analogy argument is flawed.
(E) This brings up a major shortcoming of the analogy. In the case of trade between Europe and East Asia in the early Middle Ages, there are written records where this trade would have been very likely to have been mentioned if it existed, and it's not mentioned. In that context, the "no mention" is actually very strong evidence against the existence of such trade