Match the following correctly

a Paddy	1. Detasseling
b red gram	2. CGMS
c Cotton	3. GMS
d Maize	4. Emasculation and dusting

Correct option is A

Paddy hybrid seed production uses CGMS system.
Red gram hybrids are developed using emasculation and dusting.
Cotton hybrids commonly use Genetic Male Sterility (GMS). Maize hybrid seed production involves detasseling. Thus, the correct matching is 4-2-3-1.
This combination matches standard seed production practices. Therefore, option (D) is correct.