If $$I_n = \left\{x \epsilon R: -\frac{1}{n} < x < \frac{1}{n}\right\}$$ for n = 1, 2, 3, --- ---- ---- then $$I_7 \cap I_{13} = $$

A

$$I_7$$

B

$$I_{13}$$

C

$$I_6$$

D

$$I_{20}$$