This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Endocrinology, Subject name: Pharmacology
Conversion of T4 to T3 is inhibited by all except 
Select and explain. 
A. Propanolol, B. Propylthiouracil, C. Amiodarone, D. Methimazole
D: Methimazole
Answer: D: Methimazole 
Explanation: Refer KDT 6/e p250 Methimazole inhibits only thyroid peroxidase whereas propylthiouracil inhibits thyroid peroxidase as well as 5-deiodinase. Later is involveed in peripheral conversion of T4 to T3