Having trouble with choices A and E.

Perhaps I may have it correct but I’m trying to gauge if my thinking is correct.

For choice A. This is correct because the whole notion of “destroying any diseased cow as it shows typical symptoms” matches with the support in the stimulus that BSE CANNOT be detected until overt symptoms are found—hence making choice A’s proposal impossible to help eradicate BSE as by the time a cow has been infected with BSE, it may have already exposed other cows.

However, why is choice E incorrect?

Please #help