Explanation

Option A is correct: Carbofuran, Methyl parathion, Phorate, and Triazophos are broad-spectrum, systemic organophosphate and carbamate chemical pesticides (insecticides) used in agriculture:

– They are applied to field crops like paddy, cotton, vegetables, and oilseeds to manage foliar pests, stem borers, and nematodes.
– Due to their high acute toxicity, persistence in aquatic systems, high mammalian toxicity, and hazards to birds and farmworkers, their non-judicious use is viewed with great concern, leading environmental bodies and states (such as Kerala) to enforce bans or restrictions on them.

Therefore, they are used as pesticides in agriculture — Option A.