Let $$T_k$$ denote the $$k$$th term of an arithmetic progression. Suppose there are positive integers $$m\ne n$$ such that $$T_m=\frac{1}{n}$$ and $$T_n=\frac{1}{m}$$. Then $$T_{mn}$$ equals

A

$$\frac{1}{mn}$$

B

$$\frac{1}{m}+\frac{1}{n}$$

C

1

D

0