Let R be an equivalence relation on a non-empty set A= {1,2,3…,2n} with n equivalence classes. Which of the following cannot be true?
A. If (a, b), (b, c) belongs to R then (c, a) belongs to R
B. There can be an equivalence class with size more than n+1
C. |R| <= 2n
D. |R| <= n2+3n
Please explain option D how is it Correct. I cannot get the intuition of option D.