This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Anti-HIV Drugs, Subject name: Pharmacology
[{'content': 'Which of the following Anti-retro viral agent can cause bone marrow suppression? \nSelect and explain. \nA. Ritonavir, B. Zidovudine, C. Stavudine, D. Didanosine', 'role': 'user'}, {'content': 'Answer: B \nExplanation: ZIDOVUDINE: Is a NI (NUCLEOSIDE REVERSE TRANSCRIPTASE INHIBITOR) against HIV-1, HIV-2 and HTLVs I and II. It causes Competitive inhibition but no impact on cells already infected with HIV . It causes Bone Marrow Suppression, Lipodystrophy, Erythrocytic Macrocytosis, Skeletal muscle myopathy, Hepatic toxicity and on chronic use can cause Nail hyperpigmentation', 'role': 'assistant'}]