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
Usual incubation period for hepatitis B virus infection is: 
Select and explain. 
A. 1 — 2 days, B. 1 — 2 weeks, C. 1 — 6 months, D. 1 year
C: 1 — 6 months
Answer: C: 1 — 6 months 
Explanation: None