This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pharmacology
Nausea and vomiting that are associated with administration of opioid analgesic is the result of stimulation of the 
Select and explain. 
A. Limbic system, B. Emetic system, C. Chemoreceptor trigger zone (CTZ), D. Opioid receptors in G.I.T.
C: Chemoreceptor trigger zone (CTZ)
Answer: C: Chemoreceptor trigger zone (CTZ) 
Explanation: None