On heating with chlorine, the hydrocarbon 2,2-dimethylbutane reacts by free radical substitution. During a propagation step, a free radical X$\bullet$ is produced. $\text{CH}_3\text{CH}_2{-}\text{C}(\text{CH}_3)_2{-}\text{CH}_3 + \text{Cl}\bullet \rightarrow X\bullet + \text{HCl}$ How many different structures of X$\bullet$ can there be?
- A2
- B3
- C4
- D5