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: Unknown
Magnesium sulphate potentiates the hypotensive action of - 
Select and explain. 
A. Methyldopa, B. Nifedipine, C. Enalapril, D. Hydralazine
B: Nifedipine
Answer: B: Nifedipine 
Explanation: ans-B