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: Unknown
Which of the following medications can be safely used in pregnancy - 
Select and explain. 
A. Propylthiouracil, B. Methotrexate, C. Warfarin, D. Tetracycline
A: Propylthiouracil
Answer: A: Propylthiouracil 
Explanation: Ans: A