Consider the push-down automaton M = (K, , , ,s,F) where K = {s,f}, = {a,b}, = {a,b}, F = {f}, and consists of the following transitions: ((s,a,e),(s,a)), ((s,b,e),(s,b)), ((s,a,e),(f,e)), ((f,a,a),(f,e)), ((f,b,b),(f,e)). (a) Which of the following words are in L(M)? Circle all that are. abab, aaa, aab, bbbaaabbb, aabbaa, aaaabb (b) Describe the language accepted by M in simpler terms (that is, without reference to a push-down automaton).