Which of the following sets are equal?

A = {1, 2}

B = {1, 2}

C = {3, 1}

D = {1, 3} (since, the odd natural numbers less than 5 are 1 and 3)

E = {1, 2} (since, repetition is not allowed)

F = {1, 3} (since, repetition is not allowed)

Sets A, B and E are equal.

C, D and F are equal.