GMAT Critical Reasoning (CR) | Every fall Croton's jays migrate south. The jays always join

Option C never says about south and is not a good contender for answer. It does not give thought whether Jays cannot travel to south with out help.

Option E says Crookbeaks travel with out Jays, means Jays may or may not require some one to take them to North but they require some one to take to South.

Not able to understand how Option C is better than Option E.

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