Answer: A is a subset of B.
- A A = B
- B B is a subset of A
- C A and B are disjoint
- D A is a subset of B
Correct answer: D. A is a subset of B
Explanation: A is a subset of B (A is a subset of B) means every element of A belongs to B.
A Venn diagram makes set identities visual: A∪B is everything inside either circle, A∩B is only the overlap, and the region outside both circles represents the complement of their union - directly illustrating De Morgan's law (A∪B)′ = A′∩B′.
Concept context
Types of sets, operations (union/intersection/complement), relations, and types of functions with domain and range