On heating with chlorine, the hydrocarbon $2,2$-dimethylbutane undergoes free radical substitution. During a propagation stage, the free radical $X^\bullet$ is produced. $\text{CH}_3\text{CH}_2\!\!\begin{array}{c}\text{C}\\|\\\text{CH}_3\end{array}\!\!\text{CH}_3\; + \text{Cl}^\bullet \rightarrow X^\bullet + \text{HCl}$ How many different forms of $X^\bullet$ can be formed?
- A1
- B2
- C3
- D4