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
Mechanism of action of 5–FU is : 
Select and explain. 
A. Antimetabolite, B. Direct DNA chelating agent, C. Anti-Mitotic, D. Topoisomerase inhibitor
A: Antimetabolite
Answer: A: Antimetabolite 
Explanation: None