[求助]问到lr题，大虾们多多指教了

ivy3997

Historian： There is no direct evidence that timber was traded between the ancient nations of Poran and Nayal, but the fact that a law setting tariffs on timber imports from Poran was enacted during the third Nayalese dynasty does suggest that during that period a timber trade was co9nducted.

　　Critic： Your reasoning is flawed. During its third dynasty, Nayal may well have imported timber from Poran, but certainly on today's statute books there remain many laws regulating activities that were once common but in which people no longer engage.

　　21. The critic's response to the historian's reasoning does which one of the following？

　　（A） It implies an analogy between the present and the past.

　　（B） It identifies a general principle that the historian's reasoning violates.

　　（C） It distinguishes between what has been established as a certainty and what has been established as a possibility.

　　（D） It establishes explicit criteria that must be used in evaluating indirect evidence.

　　（E） It points out the dissimilar roles that law plays in societies that are distinct from one another.

重点解释下A和C好吗，谢谢了