This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Other topics and Adverse effects, Subject name: Anatomy
A pregnant female Salma with thyrotoxicosis is planned for surgery. Before surgery can be done, her gland should be reduced in size and vascularity by administering: 
Select and explain. 
A. Iodide ion, B. Propanolol, C. Propylthiouracil, D. Radioactive iodine
C: Propylthiouracil
Answer: C: Propylthiouracil 
Explanation: (Ref: KDT 6/e p250) Iodides are commonly used to decrease the size and vascularity of thyroid gland before surgery. As this patient is pregnant, iodides and radioactive iodine is contraindicated. Propylthiouracil is safe in pregnancy and is used for this purpose.