Answer: (a, a) ∈ R for every a ∈ A.
- A (a, a) ∈ R for every a ∈ A
- B (a, b) ∈ R implies (b, a) ∈ R
- C (a, b) and (b, c) ∈ R imply (a, c) ∈ R
- D R is the empty set
Correct answer: A. (a, a) ∈ R for every a ∈ A
Explanation: Reflexivity requires every element to be related to itself.
Concept context
Types of relations, equivalence classes, one-one and onto functions, composition, and invertible functions