This problem is designed to help you understand the relationship between the properties of symmetry and anti-symmetry. Consider the following statements and check (only) the ones that are true. a. Any relation that is 'restricted to the diagonal', i. e a Rb only if a = b, is both symmetric and anti-symmetric. b. On any set, the equality relation is the only relation that is both symmetric and anti-symmetric. c. If a relation is symmetric, it can't be anti-symmetric. If even one off-diagonal relationship exists, i. e. if there is even one pair a, b with a Rb but a and b not equal, then the relation cannot be both symmetric and anti-symmetric. d. The equality relation on any set is both symmetric and anti-symmetric. e. If a relation is anti-symmetric, it can't be symmetric. f. None of the above