4. Consider the algebraic structure (S5, ). a. b. C. d. Is Ss closed under o? Explain or give a counterexample. Is (S5, ') associative? Explain or give a counterexample. Does Ss have an identity under o? Explain or give a counterexample. Does every element in Ss have an inverse under o? Explain or give a counterexample. Is (S5, ") commutative? Explain or give a counterexample. e