Suppose A is a finite set with n elements. The number of elements and the rank of the largest equivalence relation on A are

A

$$\left\{n, 1 \right\}$$

B

$$\left\{n, n \right\}$$

C

$$\left\{n^2, 1 \right\}$$

D

$$\left\{1, n^2\right\}$$