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: Gynaecology & Obstetrics
One of the following is an absolute contraindication for treatment of Thyrotoxicosis in pregnancy of 6 months duration:- 
Select and explain. 
A. Antithyroid drug, B. I131 therapy, C. Telepaque, D. Surgery
B: I131 therapy
Answer: B: I131 therapy 
Explanation: Radioactive iodine is an absolute contraindication in the treatment of thyrotoxicosis in pregnancy. In fact, it should not be given to patients even wanting pregnancy within 6 months.