Answer: empty set.
- A empty set
- B universal set
- C power set
- D singleton set
Correct answer: A. empty set
Explanation: The empty (null) set, written ∅ or { }, has no elements.
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