A 44-year-old male construction worker is brought to the emergency department 90 minutes after acute exposure to an organophosphate pesticide. He presents with severe diaphoresis, confusion, pinpoint pupils, excessive salivation, lacrimation, and urinary incontinence. On examination, he has visible muscle fasciculations, diffuse bronchospasm with wheezing, and bradycardia (HR 52 bpm). Blood pressure is 88/54 mmHg, RR 32 breaths/min, and SpO2 is 86% on room air. Red blood cell cholinesterase activity is 12% of normal. After securing the airway and initiating mechanical ventilation, which of the following agents should be administered FIRST to address his acute life-threatening symptoms?

1. A)Pralidoxime (2-PAM), which reactivates acetylcholinesterase by nucleophilic attack on the phosphoryl group
2. B)Physostigmine, an acetylcholinesterase inhibitor that increases central and peripheral acetylcholine
3. C)Atropine, a competitive antagonist at muscarinic cholinergic receptorsGABARITO
4. D)Edrophonium, a short-acting acetylcholinesterase inhibitor used diagnostically
5. E)Phenylephrine, an α1-adrenergic agonist that increases peripheral vascular resistance