Which of the following statements about the free radical chlorination of methane are correct?

A $Cl \cdot$ is a chain carrier that is regenerated in the propagation steps
BOne photon-generated chlorine atom can lead to the formation of many molecules of $CH X_{3} Cl$
CA trace of oxygen can retard the reaction by reacting with the radicals
DThe reaction proceeds through the carbocation $CH X_{3} X^{+}$

Answer: A, B, C

The reaction is a radical chain:

Cl \cdot

is consumed and regenerated, so one initiation event drives many cycles, and radical scavengers such as

O X_{2}

act as inhibitors. No carbocation is involved, so statement D is false.