Answer: Symmetric and transitive but not reflexive.
- A Symmetric and transitive but not reflexive
- B Reflexive but not symmetric
- C An equivalence relation
- D Reflexive and transitive
Correct answer: A. Symmetric and transitive but not reflexive
Explanation: With no pairs at all, symmetry and transitivity hold vacuously, but reflexivity fails since (a, a) is missing.
Concept context
Types of relations, equivalence classes, one-one and onto functions, composition, and invertible functions