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
Anti emetic action is produced through :  a) Decreased CTZ stimulation b) H1 agonistic action c) D1 antagonistic action d) Olfactory apparatus stimulation e) 5 HT4 agonistic action 
Select and explain. 
A. ab, B. ad, C. bc, D. ae
D: ae
Answer: D: ae 
Explanation: None