Right choice is (b) Thioether oxidation
The best explanation: Thioether oxidation, usually performed by microbial population by oxidizing the Sulphur present in the pesticides. Whereas, biogeochemical cycle is crucial for methanogens, the natural release of biogas in the environment is due to the activity of methanogens, hence, it can’t dissolve metals. Also, afforestation and deforestation cannot dissolve metals.