Safest chemical for honey bee is

Answer: Option C

Safest chemical for honey bees is Endosulphan.
Endosulfan is an off-patent organochlorine insecticide and acaricide that is being phased out globally. It has been used globally as a pesticide since the 1950s to control a variety of insects including whiteflies, aphids, leafhoppers, Colorado potato beetles, and cabbage worms.
Endosulfan was very much safer for honeybees than the two organophosphate insecticides.