**Core Concept**
Orphan drugs are medicinal products intended for the diagnosis, prevention, or treatment of a rare disease or condition. According to the US FDA, a rare disease is one that affects fewer than 200,000 people in the United States.

**Why the Correct Answer is Right**
Orphan drugs are granted special status by regulatory agencies to incentivize their development. This status provides benefits such as tax credits, exemptions from user fees, and market exclusivity. The Orphan Drug Act of 1983 in the United States and similar regulations in the European Union aim to encourage the development of treatments for rare diseases. These laws recognize the challenges and costs associated with researching and developing treatments for small patient populations.

**Why Each Wrong Option is Incorrect**

**Option A:** This option is incorrect because it does not accurately describe the primary purpose of orphan drug designation.
**Option B:** This option is incorrect as it suggests that orphan drugs are only for diseases with no other treatment options, which is not a requirement for designation.

**Clinical Pearl / High-Yield Fact**
A key aspect of orphan drug designation is the provision of market exclusivity, which can last up to seven years in the United States. This exclusivity prevents other companies from marketing the same drug for the same condition during this period, providing a significant incentive for companies to develop orphan drugs.

**Correct Answer: C. Orphan drugs are medicinal products intended for the diagnosis, prevention, or treatment of a rare disease or condition.**