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: Pharmacology
Phocomelia is an adverse effect due to: 
Select and explain. 
A. Thalidomide, B. Warfarin, C. Enalapril, D. Phenytoin
A: Thalidomide
Answer: A: Thalidomide 
Explanation: Thalidomide