## **Core Concept**
The posterior cerebral artery (PCA) is a vital blood vessel that supplies oxygenated blood to the occipital lobe, the inferior part of the temporal lobe, and various deep structures. Infarcts in the PCA territory can lead to a range of neurological deficits, including visual disturbances. Understanding the PCA's territory is crucial for diagnosing and managing stroke patients.

## **Why the Correct Answer is Right**
The PCA primarily supplies the occipital lobe, which is responsible for processing visual information, and parts of the temporal lobe. The areas typically involved in a PCA infarct include the occipital lobe, the posterior part of the temporal lobe, and sometimes the thalamus and choroid plexus of the third and lateral ventricles. The correct answer, which is not involved in a PCA infarct, would be a region outside this typical territory.

## **Why Each Wrong Option is Incorrect**
- **Option A:** This option might involve areas typically supplied by the PCA, such as parts of the occipital or temporal lobes. Therefore, it could be involved in a PCA infarct.
- **Option B:** Similarly, this might include regions within the PCA territory, making it a potential site for involvement in a PCA infarct.
- **Option C:** This could also represent areas supplied by the PCA, such as the occipital lobe or parts of the temporal lobe, which can be affected in a PCA infarct.

## **Clinical Pearl / High-Yield Fact**
A key clinical pearl is that PCA infarcts often present with visual field defects, such as homonymous hemianopia. This is because the occipital lobe, which is commonly affected, plays a critical role in processing visual information. Recognizing this association can help in quickly identifying the likely cause of a patient's symptoms.

## **Correct Answer: D.**