This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Pharmacology
The following receptor has an intrinsic ion channel 
Select and explain. 
A. Histamine H1 receptor, B. Histamine H2 receptor, C. Adrenergic alfa receptor, D. GABA-benzodiazepine receptor
D: GABA-benzodiazepine receptor
Answer: D: GABA-benzodiazepine receptor 
Explanation: GABA -BDZ receptor is an ion channel receptor , has an intrinsic Cl ion channel opening when a agonist binds to it and causes increase in frequency of channel opening and causes hyperpolarization. KDT 6/ e pg 42