Identify incorrect statements
A) Ethoxide ion $\left(C_2{H}_5{O}^{\mathbf{-}}\right)$ is a nucleophile
B) Bromonium ion $\left(B{r}^{\mathbf{+}}\right)$ is an electrophile
C) $H_3 C- C\equiv N$contains both electrophilic and nucleophilic centres
D) Methyl free radical $\left(\stackrel{\bullet }{\mathrm{C}}{\mathrm{H}}_3\right)$ is diamagnetic