This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General pharmacology, Subject name: Pharmacology
Which of the following drugs do not act through the ion channel receptors 
Select and explain. 
A. Nicotine, B. Insulin, C. Gliclazide, D. Diazepam
B: Insulin
Answer: B: Insulin 
Explanation: Insulin acts through enzyme-linked receptor - tyrosine kinase acts through: gliclazide- potassium channels, nicotine-nicotinic acetylcholine channels, diazepam- GABA channels Ref: KD Tripathi 8th ed