This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Autacoids, Subject name: Pharmacology
The receptor involved in chemotheraphy induced vomiting is: 
Select and explain. 
A. Histamine H1 receptor, B. Serotonin 5-HT3 receptor, C. Dopamine D2 receptor, D. Opioid m receptor
B: Serotonin 5-HT3 receptor
Answer: B: Serotonin 5-HT3 receptor 
Explanation: Ondansetron:- It is the prototype of the new class of selective 5-HT3 antagonists that have shown efficacy in controlling nausea and vomiting following administration of highly emetic anticancer drugs and radiotherapy. Ref:- kd tripathi; pg num:-175 Ondansetron is the DOC for early vomiting and nausea due to chemotheraphy and radiotherapy.