This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Drugs, Subject name: Medicine
[{'content': 'Phocomelia is caused by ingestion of ------ during pregnancy: \nSelect and explain. \nA. Steroids, B. Tetracycline, C. Thalidomide, D. Barbiturates', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Ans: cRef: Harrison, 15th ed, p. 1038', 'role': 'assistant'}]