Correct Option: C

Malathion is an organophosphate parasympathetic which binds irreversibly to cholinesterase. Malathion is an insecticide of relatively low human toxicity. However, malathion breaks down into malaoxon, which is 60 times more toxic than malathion. For this reason, if malathion is used or somehow enters an indoor environment, as it breaks down into malaoxon, it can seriously and chronically poison the occupants living or working in this environmnent. Malathion present in untreated water is converted to malaoxon during the chlorination phase of water treatment, so malathion should not be used in waters that may be used as a source for drinking water, or any upstream waters.