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: Medicine
XDR -TB is resistant to - 
Select and explain. 
A. AKT (HRZE), B. HRKN, C. HRKO, D. HREEt
C: HRKO
Answer: C: HRKO 
Explanation: None