**Core Concept**
In multibacillary leprosy, a follow-up examination is crucial to assess the effectiveness of treatment and detect any potential relapse. The World Health Organization (WHO) recommends a specific duration for follow-up examinations after adequate treatment.

**Why the Correct Answer is Right**
The correct duration for follow-up examinations in multibacillary leprosy is 5 years. This is because multibacillary leprosy is a more severe form of the disease, characterized by a higher bacterial load and a greater risk of relapse. The 5-year follow-up period is essential to ensure that the patient has achieved sustained remission and to detect any potential complications, such as neuropathy or skin lesions. During this period, the patient's skin lesions, nerve function, and overall health status are closely monitored to prevent any long-term sequelae.

**Why Each Wrong Option is Incorrect**
**Option A:** 3 years is the recommended follow-up period for paucibacillary leprosy, not multibacillary leprosy.
**Option B:** This option is a duplicate of Option A and is incorrect for the same reason.
**Option D:** 10 years is excessive and not recommended by the WHO for follow-up examinations in multibacillary leprosy.

**Clinical Pearl / High-Yield Fact**
It is essential to differentiate between multibacillary and paucibacillary leprosy, as the treatment and follow-up regimens differ significantly between the two forms of the disease. Multibacillary leprosy requires a more prolonged follow-up period to prevent relapse and long-term complications.

**✓ Correct Answer: C. 5 years**