Cyanide ions react with bromoethane, giving propanenitrile. Which statement correctly describes the $\text{S}_\text{N}2$ mechanism for this reaction?
- AThe lone pair of electrons on C of $\text{CN}^-$ attacks the carbon atom of the C-Br bond.
- BThe lone pair of electrons on C of $\text{CN}^-$ attacks the carbocation formed when the C-Br bond breaks.
- CThe lone pair of electrons on N of $\text{CN}^-$ attacks the carbon atom of the C-Br bond.
- DThe lone pair of electrons on N of $\text{CN}^-$ attacks the carbocation formed when the C-Br bond breaks.