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
Protease inhibitors are : a) Saquinavir b) Nevirapine c) Nelfinavir d) Abacavir e) Efavirenz 
Select and explain. 
A. ac, B. be, C. bc, D. ad
A: ac
Answer: A: ac 
Explanation: None