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
Which of the following blocks replication without getting involved in the DNA strand ? a) Cytarabine b) Nalidixic acid c) Ciprofloxacin d) 5–Fluorouracil e) 6–Mercaptopurine 
Select and explain. 
A. be, B. cd, C. bc, D. bd
C: bc
Answer: C: bc 
Explanation: None