**Core Concept**
Poliovirus shedding in stool is a critical aspect of poliomyelitis transmission. It is essential to understand the duration of viral shedding to implement effective public health measures and assess the risk of disease transmission.

**Why the Correct Answer is Right**
Poliovirus shedding in stool typically lasts for 3-4 weeks after the onset of symptoms, but in some cases, it can persist for up to 12 weeks. This prolonged shedding period increases the risk of transmission, especially in areas with poor sanitation and hygiene. The prolonged shedding period is due to the presence of the virus in the gut-associated lymphoid tissue (GALT), where it can persist for an extended duration.

**Why Each Wrong Option is Incorrect**
**Option A:** 6 weeks - This duration is shorter than the actual shedding period, which can last up to 12 weeks.
**Option B:** 8 weeks - While this option is closer to the correct answer, it still underestimates the maximum duration of viral shedding.
**Option C:** 10 weeks - This option is also incorrect as it does not account for the prolonged shedding period.

**Clinical Pearl / High-Yield Fact**
It is essential to note that poliovirus shedding can occur even in individuals who are asymptomatic or have a minor illness, making it crucial to implement vaccination programs and maintain high levels of herd immunity to prevent transmission.

**✓ Correct Answer: D. 12 weeks**