d
Carbon and Nitrogen has a unique ability to form $\mathrm{p} \pi-\mathrm{p} \pi$ multiple bonds with itself and with other atoms of small size and high electronegativity.
Few examples of multiple bonding are $\mathrm{C}=\mathrm{C}, \mathrm{C}=\mathrm{O}, \mathrm{N}=\mathrm{C}$
Hence option D is a correct answer.