If A = {1, 2, {3, 4}}, which of the following is a true statement?
Answer: B
The elements of set A are 1, 2, and the set {3, 4}.
Option A is false because 3 is not an element of A; it's an element of the element {3, 4}.
Option B is true because 1 and 2 are elements of A, so the set containing them, {1, 2}, is a subset of A.
Option C is false because {3, 4} is an element of A, not a subset. For it to be a subset, 3 and 4 would have to be elements of A themselves.
Option D is false for the same reason as A.