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
The drug of choice for treatment of thyrotoxicosis during pregnancy is 
Select and explain. 
A. Iodine therapy, B. Carbimazole, C. Propylthiouracil, D. Methimazole
C: Propylthiouracil
Answer: C: Propylthiouracil 
Explanation: Refer KDT 6 /e p 250 Propylthiouracil does not cross placenta and us therefore The drug of choice in first trimester pregnancy