Which of the following is an antidote for organophosphate poisoning?

Atropine is an established antidote for organophosphate poisoning due to its ability to counteract the effects of acetylcholine accumulation caused by organophosphates, which inhibit the enzyme acetylcholinesterase. Organophosphates disrupt normal nerve function by preventing the breakdown of acetylcholine, leading to excessive stimulation of the nervous system. By antagonizing the effects of acetylcholine at muscarinic receptors, atropine alleviates symptoms such as salivation, lacrimation, urination, diarrhea, gastrointestinal distress, and bradycardia that are associated with organophosphate toxicity.

Rhodamine B, while a chemical dye, does not possess any therapeutic properties for treating organophosphate poisoning. Lindane is an insecticide, and while it may have some neurotoxic effects, it does not serve as an antidote for organophosphate poisoning. Chlorpyrifos is another organophosphate insecticide and would actually exacerbate the condition if involved in the poisoning scenario, rather than providing any antidotal effect. Therefore, the selection of atropine is crucial in the treatment of organophosphate poisoning to restore normal physiological function.