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
A patient presents with nephrotic syndrome and hypoalbuminemia. Protein binding of which drug is not affected - 
Select and explain. 
A. Tolbutamide, B. Morphine, C. Diazepam, D. Valproate
B: Morphine
Answer: B: Morphine 
Explanation: Ans. is 'b' i.e., Morphine in nephrotic syndrome there is no effect on protein binding. o Other three drugs are plasma protein bound drugs.