The major product 'P' formed in the following reaction is:

The correct answer is option 1.

The given reactant is 1-ethyl benzene. During chlorination and in the presence of light or heat, the alkyl side chain is substituted.

When 1-ethylbenzene reacts with chlorine in presence of light or heat, then it results in the formation of

1-chloro-1-phenylethane and 2-chloro-1-phenylethane.

In this reaction, 1-chloro-1-phenylethane is a major product and 2-chloro-1-phenylethane is a minor product.

Chlorination of ethylbenzene in a nucleophilic substitution reaction. The stability of the carbocation affects the formation of the major product. A more stable secondary carbocation is produced when a nucleophile attacks α carbon atom.

Since it is a secondary alkyl halide, 1-chloro-1-phenylethane is a major product.