This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: NEET Jan 2020, Subject name: Pharmacology
Which of the following drugs act by inhibiting DNA replication? 
Select and explain. 
A. 6 Mercaptopurine, B. Actinomycin D, C. Mitomycin C, D. Asparaginase
A: 6 Mercaptopurine
Answer: A: 6 Mercaptopurine 
Explanation: 6 Mercaptopurineis purine antimetabolite therefore it preventsDNAreplication. Mitomycin C is an antitumor antibiotic that inhibits DNA synthesis by producing DNA cross-links which halt cell replication and eventually cause cell death. Actinomycin D acts by inhibiting DNA dependent RNA synthesis. Asparaginase is an enzyme that catalyzes the hydrolysis of l-asparagine to l-aspaic acid and ammonia. They inhibit protein synthesis in tumor cells by depriving them of the amino acid asparagine.