In following question which of ∅, A, and B are subsets of B?
1. A = 1, 2, 3, 4} and B = {1, 2, 3, 4, 5, 6}
2. A = {a, b, c, d} and B = {c, d, a, b}?
3. Is A ( B if A = {a, b, c, d} and B = {a, b, d}?
4. Is A ( B if A = {6, 8, 10, 12} and B = {6, 8, 10, 14, 18}?