This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Toxicology, Subject name: Medicine
A farmer with long history depression on antidepressants, consumed unknown substance and presented with bradycardia, hypersalivation, small pupils. What is the most probable diagnosis? 
Select and explain. 
A. OP poisoning, B. Atropine, C. TCA, D. Paracetamol poisoning
A: OP poisoning
Answer: A: OP poisoning 
Explanation: Ans: A (OP poisoning) Ref: Harrison's Principles of internal Medicine. 18th edn.Explanation:MiosisMydriasisCholinergicsAnticholinergicsAntipsychoticsSympathomimeticsCarbamatesSSRIsOrganophosphatesSedative - hypnotics withdrawalOpioidsAlcohol Withdrawal syndromeClonidine Sedative - Hyponotics Clinical Features of Orqanophosphate PoisoningMuscarinic effectsCVS: Bradycardia , HypotensionResp: Rhinorrhea. Bronchorrhea,BronchospasmGIT: Hypersalivatioa Nausea and Vomiting, Abdominal pain. Diarrhea,Fecal incontinence. Urinary incontinenceOcular: Miosis, Blurred vision Glands: Increased lacrimation, DiaphoresisNioctinic effectsMuscle fasciculationsCrampingWeaknessDiaphragmatic paralysis Autonomic nicotinic effects(Mild): Tachycardia, Hypertension, Mydriasis and pallorCNS effectsAnxietyEmotional labilityRestlessnessConfusionAtaxiaT remorsSeizuresComa