## **Core Concept**
Horner's syndrome is a neurologic disorder characterized by a triad of ptosis, miosis, and anhidrosis, resulting from disruption of the sympathetic nerves supplying the eye. This disruption can occur at various levels, including the brain, spinal cord, or peripheral nerves.

## **Why the Correct Answer is Right**
The correct answer is related to the characteristic features of Horner's syndrome. Typically, Horner's syndrome presents with ptosis (drooping eyelid), miosis (pupillary constriction), and anhidrosis (absence of sweating) on the affected side of the face. The ptosis is usually mild, and the pupil is smaller but still reacts to light and accommodation.

## **Why Each Wrong Option is Incorrect**
- **Option A:** This option is not provided, but generally, correct statements about Horner's syndrome include ptosis, miosis, and anhidrosis.
- **Option B:** Similarly, without the specific content, we assume that accurate descriptions of Horner's syndrome features would be correct.
- **Option D:** Again, lacking the specific details, we focus on the fact that the question seeks an exception to true statements about Horner's syndrome.

## **Clinical Pearl / High-Yield Fact**
A key clinical pearl is that in Horner's syndrome, the ptosis is typically mild (about 1-2 mm drooping), and the pupil's reaction to light and accommodation is preserved. A notable exception in clinical presentation can be seen in congenital Horner's syndrome, where there might be heterochromia iridum (different colored irises).

## **Correct Answer:** .