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 is not a prodrug: 
Select and explain. 
A. Lisinopril, B. Methyldopa, C. Enalapril, D. None of the above
A: Lisinopril
Answer: A: Lisinopril 
Explanation: Lisinopril