Step 1: Recall the natural history of HIV infection.
After primary infection, there is an acute retroviral syndrome followed by an asymptomatic phase. During this phase, the virus replicates slowly, and CD4+ T cells gradually decline.
Step 2: Duration of asymptomatic period.
Most HIV-infected individuals remain asymptomatic for several years before progressing to AIDS. This period typically lasts 2–10 years, depending on host immunity, viral load, and treatment availability.
Step 3: Exclude other options.
- (A) 0<1: Too short; only applies to rapid progressors.
- (B) 1<2: Rare, seen in faster progressors.
- (C) 2<10: Correct for majority of patients.
- (D) 10 or more: Possible in long-term non-progressors but not the typical course.
Step 4: Conclusion.
Thus, the asymptomatic period in most HIV patients lasts between 2 and 10 years.