Let s be a set and p(s) be the power set of s. then {p(s), u} is not a group beccause a. p(s) is not closed w.r.to u. b. u 1s not associatıve. c. inverse does n

Let S be a set and P(S) be the power set of S. Then {P(S), u} is not a group beccause A. P(S) is not closed w.r.to U. B. U 1S not associatıve. C. inverse does not exist. D. the identity clement does not exist. O A O B Oc OD 1 point Every automorphism fof the rational numbers Qunder addition to itself has the form (a) f(x)-xf(1) (b) f(x)=xf(1) () f(xX)-=xf() or -xt(1) (d) None of these O A OB Oc O D