Answer: 1.
- A 1
- B 0
- C 2
- D infinitely many
Correct answer: A. 1
Explanation: The empty set has 2⁰ = 1 subset (itself), so its power set has one element.
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