Let R be an equivalence relation on the set A = {1, 2, 3, 4, 5}. Assume that 1R3 and 3R4. Given these conditions, which ordered pairs must belong to R? (Hint: there are at least 11 such elements.)
a) (1, 1), (1, 2), (1, 3), (1, 4), (1, 5)
b) (3, 1), (3, 2), (3, 3), (3, 4), (3, 5)
c) (4, 1), (4, 2), (4, 3), (4, 4), (4, 5)
d) (5, 1), (5, 2), (5, 3), (5, 4), (5, 5)