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
All are true about Sodium nitroprusside except 
Select and explain. 
A. It acts on endothelium to produce Nitric Oxide, B. Drug of choice for Hypertensive emergency, C. It is both arterial & veno-dillator, D. It can cause hypothyroidism
B: Drug of choice for Hypertensive emergency
Answer: B: Drug of choice for Hypertensive emergency 
Explanation: Sodium nitroprusside is used as a second line treatment for Hypertensive emergency (DOC is Nicardipine).
It is a mixed vasodilator which acts on endothelium to release Nitric oxide (NO).
It is metabolized by liver to produce thiocyanate and may cause hypothyroidism.