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
Sterility is caused by : 
Select and explain. 
A. Vinca alkaloids, B. Alkylating agents, C. Antimetabolites, D. Actinomycin D
B: Alkylating agents
Answer: B: Alkylating agents 
Explanation: None