**Core Concept**
Subclavian steal syndrome is a vascular condition that occurs due to the stenosis or occlusion of the subclavian artery proximal to the origin of the vertebral artery. This leads to reversal of blood flow in the vertebral artery, causing a characteristic hemodynamic steal phenomenon.

**Why the Correct Answer is Right**
In subclavian steal syndrome, the stenotic or occluded subclavian artery creates a pressure gradient between the arm and the head. As a result, blood flow is diverted from the arm to the brain through the vertebral artery, which originates from the subclavian artery. This diversion of blood flow leads to reversal of blood flow in the vertebral artery, particularly during arm exercise or hypertension. The reversal of blood flow is due to the higher pressure in the arm compared to the head, which causes blood to flow from the arm to the head through the vertebral artery.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not specify the correct vessel involved in subclavian steal syndrome. While the vertebral artery is indeed affected, the reversal of blood flow is a characteristic feature of the condition.

**Option B:** This option is incorrect because it does not accurately describe the hemodynamic changes that occur in subclavian steal syndrome. The reversal of blood flow is not a result of the stenosis or occlusion of the carotid artery.

**Option C:** This option is incorrect because it does not specify the correct vessel involved in subclavian steal syndrome. While the internal carotid artery is a critical vessel for cerebral blood flow, it is not directly affected by the stenosis or occlusion of the subclavian artery.

**Option D:** This option is incorrect because it does not accurately describe the hemodynamic changes that occur in subclavian steal syndrome. The reversal of blood flow is not a result of the stenosis or occlusion of the brachiocephalic artery.

**Clinical Pearl / High-Yield Fact**
A key clinical feature of subclavian steal syndrome is the presence of a "subclavian steal" murmur, which is a high-pitched, continuous murmur heard over the supraclavicular region. This murmur is due to the turbulent blood flow through the vertebral artery during arm exercise or hypertension.

**Correct Answer:** C.