**Question:** True about vertebral artery -

A. It is a branch of the subclavian artery.
B. It supplies blood to the brain.
C. It runs through the carotid canal in the transverse process of the cervical vertebrae.
D. It does not have any branches after entering the skull base.

**Correct Answer:**

**Core Concept**: The vertebral artery is a significant artery in the neck, as it is responsible for supplying blood to the brain and plays a crucial role in the circulation system.

**Why the Correct Answer is Right:**

A. **Correct**: The vertebral artery indeed arises as a branch from the subclavian artery, which is a major artery in the neck that carries oxygenated blood from the heart to the head and neck.

B. **Correct**: The primary function of the vertebral artery is to supply blood to the brain, specifically the posterior circulation, which includes the cerebellum, brainstem, and the basilar artery.

C. **Core Concept**: The vertebral artery travels through a specialized canal known as the carotid canal, found in the transverse process of the cervical vertebrae. This protects the artery and keeps it safe from injury.

D. **Incorrect**: While the vertebral artery does enter the skull base, it does not remain unbranched after that point. In fact, it gives rise to several branches, including the posterior cerebral artery, the basilar artery, and the vertebrobasilar junction.

**Why Each Wrong Option is Incorrect:**

A. **Option A**: While the vertebral artery does branch out into smaller vessels, it continues to play a vital role in supplying blood to the brain, making this option incorrect.

B. **Option B**: Although the vertebral artery is essential for supplying blood to the brain, this option is wrong because the artery does not remain unbranched after entering the skull base.

C. **Option C**: While it is true that the vertebral artery travels through the carotid canal, this option is incorrect because the artery does branch out into other key structures after entering the skull base.

D. **Option D**: This option is incorrect because even after entering the skull base, the vertebral artery continues to supply blood to the posterior circulation, making it essential in maintaining cerebral blood flow.

**Why the Correct Answer is Right**:

The correct answer (C) highlights that the vertebral artery travels through the carotid canal in the transverse process of the cervical vertebrae. This anatomical feature helps protect the artery from injury and allows it to safely traverse through the cervical spine. However, this option is incorrect because the artery does branch out into several other structures after entering the skull base.

**Why Each Wrong Option is Incorrect**:

A. Option A is incorrect because the vertebral artery continues to play a vital role in supplying blood to the brain, which is a crucial task of the vertebral artery.

B. Option B is incorrect because the vertebral artery does branch out into smaller vessels after entering the skull base, contributing to the posterior circulation.

C. Option C is incorrect as the