This question is about the pumping lemma for context-free languages. Let B = {ww | w belongsto {a, b}*}. Suppose you are trying to prove that B is not context-free using the pumping lemma for context-free languages. Your proof starts (correctly) like this: Suppose for a contradiction that B is context-free. Let p be the pumping length given by the pumping lemma for context-free languages. Now you have to choose string s. Give a good choice for s and complete the proof