Answer: Symmetric but not reflexive.
- A Reflexive and symmetric
- B Transitive and reflexive
- C Not symmetric
- D Symmetric but not reflexive
Correct answer: D. Symmetric but not reflexive
Explanation: If A is a sibling of B then B is a sibling of A, but nobody is their own sibling.
Concept context
Types of relations, equivalence classes, one-one and onto functions, composition, and invertible functions