The correct structure of DDT is;

The correct answer is Option (2) → \( \ce{Cl3C-CH(C6H4Cl)2} \) with both Cl atoms para

The name of DDT, p,p′-dichlorodiphenyltrichloroethane, gives its structure part by part:

• Trichloroethane: a two-carbon chain, with three chlorine atoms on one carbon, \( \ce{CCl3-} \).

• Diphenyl: two benzene rings on the other carbon, which also keeps one hydrogen.

• p,p′-Dichloro: one chlorine on each benzene ring, in the para position.

    \( \displaystyle \ce{Cl3C-CH(C6H4Cl)2} \quad (\text{Cl para on each ring}) \)

Only the structure in Option (2) has all these features, so it is DDT.

NCERT (2026-27 edition):
p,p′-Dichlorodiphenyltrichloroethane (DDT) – “DDT, the first chlorinated organic insecticides, was originally prepared in 1873 …”