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: Biochemistry
Which of the following blocks DNA replication with getting incorporated in DNA strand: 
Select and explain. 
A. Cytarabine, B. Nalidixic acid, C. Ciprofloxacin, D. Paclitaxel
A: Cytarabine
Answer: A: Cytarabine 
Explanation: A i.e. Cytarabine