4. Recall that P(S) denotes the power set of S, which is the set of all subsets of S. Let A and B be sets. (a) (4 points) Is it true that P(A) U P(B) C P(AUB)? If so, prove it. If not, provide a counterexample. P(AUB)? If so, prove it. If not, provide a = (b) (4 points) Is it true that P(A) U P(B) = counterexample.