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 drugs is currently widely used in treating opioid-dependent individuals? 
Select and explain. 
A. Codeine, B. Methadone, C. Alphaprodine, D. Pentazocine
B: Methadone
Answer: B: Methadone 
Explanation: None