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
Sumatriptan is : 
Select and explain. 
A. 5HT1D antagonist, B. 5HT1A agonist, C. 5HT1D agonist, D. 5HT1A antagonist
C: 5HT1D agonist
Answer: C: 5HT1D agonist 
Explanation: None