Which is a pro-insecticide?

Answer: Option D

Pro-insecticide is Padan, Cartap and Thiocyclam.
A compound that, on administration, must undergo chemical conversion by metabolic processes before becoming the pharmacologically active insecticide is a proinsecticide.
Padan is a systemic insecticide highly effective against chewing, sucking and boring insects. It is registered for use in rice, crucifiers, cucurbits, onion, potato and mango.
Cartap [S,S ′-(2-dimethylaminotrimethylene)- bis(thiocarbamate)] is a pesticide that was first introduced in Japan in 1967 and has been commonly used to control weeds and caterpillars. Thiocyclam hydrogen oxalate (Evisect) is a broad-spectrum synthetic insecticide used to control the sucking and chewing pets on a variety of crops.