**Core Concept**
Central retinal artery occlusion (CRAO) is a medical emergency characterized by sudden, unilateral vision loss due to blockage of the central retinal artery. This condition often results in a characteristic 'cherry red spot' in the affected eye, indicating retinal edema and ischemia.

**Why the Correct Answer is Right**
In CRAO, the characteristic features include sudden vision loss, afferent pupillary defect, and a 'cherry red spot' on fundoscopy. The 'cherry red spot' is due to the persistence of the foveal circulation, which is supplied by the choroid, while the rest of the retina is ischemic. This occurs because the central retinal artery is responsible for supplying the inner retinal layers, whereas the fovea receives its blood supply from the choroid.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because afferent pupillary defect is indeed a feature of CRAO, as the affected eye has reduced pupillary constriction in response to light.
**Option B:** This option is incorrect because a 'cherry red spot' is a hallmark of CRAO, indicating retinal ischemia and edema.
**Option C:** This option is incorrect because sudden vision loss is a common presentation of CRAO, often described as a curtain of darkness descending over the visual field.

**Clinical Pearl / High-Yield Fact**
It is essential to recognize the 'cherry red spot' as a critical feature of CRAO, as prompt treatment with carotid angioplasty or anticoagulation may be beneficial in improving visual outcomes.

**Correct Answer: Not Provided**
Please provide the correct answer options for a complete explanation.