If A = (2, 4, 5, 7) and B = (3, 4, 7), then BA is?

{3}

{2, 5}

{3, 4, 7}

None of these

Set Difference (B A) means the elements in B that are not in A.

Given:

A = {2, 4, 5, 7}

B = {3, 4, 7}

Elements of B are {3, 4, 7}.

4 and 7 are also in A, so they are removed.

3 is not in A, so it remains.

Therefore, B A = {3}