Let A = {w elementof {a, b}*| w contains more a's than b's }. Suppose you are trying to prove that A is not regular using the pumping lemma. Your proof starts (correctly) like this: Suppose for a contradiction that A is regular. Let p be the pumping length given by the pumping lemma. Now you have to choose string s. For each choice of s below, state whether or not this choice of s can be used to finish the proof that A is not regular. If your answer is YES you do not have to explain anything. If your answer is NO, you should also briefly explain why it cannot be used. (a) s = a^p + 1 b. (b) s = a^p + 1 b^p. (c) s = a^p b^p. (d) s = (ab)^p a. (e) s = baa. (f) s = b^p a^p + 1