Consider three students (A, B, C) matching with three mentor…

Consider three students (A, B, C) matching with three mentors (X, Y, Z). Their preference lists are as follows: Students (Group P): A: Y, X, Z B: X, Y, Z C: X, Z, Y Mentors (Group R): X: B, C, A Y: C, A, B Z: A, B, C Current Matching M: (A, Z) (B, Y) (C, X) Question: Which of the following pairs is unstable with respect to the matching M?