24) A function f : R - R is said to be odd if f(-x) = -f(x) for all x E R. The graph of f (x) is: symmetric about the x-axis. b) symmetric about the y-axis. c) symmetric about the origin. d) None of the above. 28) Let X = {1, 2, 3, 4, 5} and let P(X ) = {A | AC X} be the power set of X. That is the set of all subsets of X. Define the function f : P(X) - NU{} be given by f(A) = [A|. Then f-'({0}) =? a) 0 b) {0} c) 0 d) None of the above. 29) Let N = {1, 2,3, ...} and let R be the real numbers. Let A = {2, 3, 4, .. .} and B = {2, 4, 6, . . .}. Which of the following statements is true. a) [N| # |A| since A is a proper subset of N. b) IN| = [B| since f(n) = 2n is a 1 - 1 and onto function from N to B. c) IN| = [R) because both sets are infinite. d) All of the above