Consider the following four rules that recursively define set S Rule 1: AA is an element of S Rule 2: If x is an element of S, then AxA is an element of S Rule 3: If y and z are elements of S, then ye is an element of S Rule: All of the elements of S can be obtained using rules 1,2, and 3 and repetitions of those rules Which of the following is an element of set S