**Core Concept**
Elimination of leprosy is a public health goal aimed at reducing the disease's prevalence to a level where it no longer poses a public health threat. This definition is based on the World Health Organization's (WHO) strategy to control and eliminate leprosy.

**Why the Correct Answer is Right**
The correct answer is based on the WHO's definition of leprosy elimination, which is achieved when the prevalence of leprosy is reduced to less than 1 case per 10,000 population. This threshold is used to determine whether a country has eliminated the disease. Leprosy elimination is not the same as eradication, which would require the complete removal of the disease from the population.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because it does not accurately reflect the WHO's definition of leprosy elimination. The correct prevalence threshold is less than 1 case per 10,000 population, not 1 case per 100 population.
* **Option B:** This option is incorrect because it suggests that leprosy elimination is achieved when the disease is eradicated, which is not the case. Elimination is a public health goal that aims to reduce the disease's prevalence to a level where it no longer poses a threat.
* **Option C:** This option is incorrect because it does not provide a specific prevalence threshold, making it an ambiguous and incorrect definition of leprosy elimination.

**Clinical Pearl / High-Yield Fact**
It's essential to remember that leprosy elimination is a public health goal, not the same as eradication. The WHO's definition of leprosy elimination is crucial for understanding the disease's control and elimination efforts.

**Correct Answer:** C.