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: Medicine
Infective endocarditis due to pseudomonas is most commonly seen with: 
Select and explain. 
A. Intravenous drug abuse of pentazocin., B. HIV patient., C. Chronic steroid therapy., D. Elderly with community acquired pneumonia.
A: Intravenous drug abuse of pentazocin.
Answer: A: Intravenous drug abuse of pentazocin. 
Explanation: None