JEE MAIN - Chemistry (2008 - No. 29)

Which one of the following constitutes a group of the isoelectronic species?

$$C_2^{2 - }$$, $$O_2^{-}$$, CO, NO

$$NO^{+}$$, $$C_2^{2 - }$$, CN^-, $$N_2$$

CN^-, $$N_2$$, $$O_2^{2-}$$, $$C_2^{2 - }$$

$$N_2$$, $$O_2^{-}$$, $$NO^{+}$$, CO

So, option $$(B)$$ is correct.