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
Which of the following are alkylating agents ? a) Cyclophosphamide b) Ifosfamide c) Paclitaxel d) Methotrexate e) Vincristine 
Select and explain. 
A. ad, B. c, C. ab, D. ac
C: ab
Answer: C: ab 
Explanation: None