This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Poisoning, Subject name: Forensic Medicine
In organophosphorus compound poisoning, organophosphorus compound actions are - 
Select and explain. 
A. Phosphorylates enzyme, B. Irreversibly inhibit cholinesterase, C. Oximes effective when given beyond 24 hours, D. Atropine can't reverse in early stage
A: Phosphorylates enzyme
Answer: A: Phosphorylates enzyme 
Explanation: Mechanism of Action Organophosphorus compounds are inhibitors of acetylcholinesterase by phosphorylating the enzyme. Acetyl cholinesterase is required to hydrolyse acetylcholine to choline and acetic acid As a result, there is accumulation of acetylcholine with continued stimulation of local receptors and eventual paralysis of nerve or muscle . Organophosphate intoxication leads to characteristic end-plate abnormalities that reflect the degree of AchE inhibition and increase in Ach concentration at the neuromuscular junction. REF;THE SYNOPSIS OF FORENSIC MEDICINE:KS NARAYANA REDDY;28th EDITION;PAGE NO 291