**Core Concept**
Cerebral angiography is a medical imaging technique used to visualize the blood vessels in the brain. It involves the injection of a contrast agent (dye) into the blood vessels to highlight their structure and any potential abnormalities.

**Why the Correct Answer is Right**
The correct answer involves the internal carotid artery (ICA), which is a major artery that supplies blood to the brain. To perform cerebral angiography, the dye is injected through a catheter placed in the ICA, allowing it to flow through the blood vessels and provide detailed images of their structure. This is typically done under fluoroscopic guidance to ensure accurate placement of the catheter.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because the vertebral artery primarily supplies blood to the posterior circulation of the brain, which is not the primary focus of cerebral angiography.
**Option B:** This option is incorrect because the external carotid artery primarily supplies blood to the face and scalp, rather than the brain itself.
**Option C:** This option is incorrect because the aorta is the largest artery in the body, but it is not the primary site for injecting contrast agents during cerebral angiography.

**Clinical Pearl / High-Yield Fact**
A common complication of cerebral angiography is cerebral vasospasm, which can occur due to the injection of contrast agents into the blood vessels. This can lead to a temporary reduction in blood flow to the brain, potentially causing stroke or other neurological deficits.

**Correct Answer:** C. Internal carotid artery.