**Core Concept**
The anatomical differences between cervical and thoracic vertebrae are crucial for understanding spinal anatomy and its clinical implications. Cervical vertebrae exhibit unique features that distinguish them from the more uniform thoracic vertebrae.

**Why the Correct Answer is Right**
The presence of a foramen transversarium is a characteristic feature of cervical vertebrae. This opening allows the vertebral artery and vein, as well as the transverse cervical nerve, to pass through and supply the cervical spine. In contrast, thoracic vertebrae do not have foramina transversaria, as the vertebral arteries and veins pass through the foramina of the transverse processes in the thoracic region. The foramen transversarium is a key distinguishing feature between cervical and thoracic vertebrae.

**Why Each Wrong Option is Incorrect**
**Option A:** A triangular body is not a characteristic feature of cervical vertebrae. While the vertebral bodies in the cervical region are generally smaller and more anteriorly directed than in the thoracic region, they are not triangular in shape.

**Option C:** The superior articular facets of cervical vertebrae are directed anteriorly, not backwards and upwards. This orientation allows for greater flexion and rotation of the cervical spine.

**Option D:** Cervical vertebrae typically have smaller vertebral bodies compared to thoracic vertebrae. The vertebral bodies in the cervical region are designed for flexibility and mobility, rather than providing support and protection for vital organs.

**Clinical Pearl / High-Yield Fact**
When identifying vertebrae in the cervical and thoracic regions, remember that the presence or absence of a foramen transversarium can be a reliable indicator of the vertebral level. This knowledge can be crucial in radiographic interpretation and surgical planning.

**✓ Correct Answer: B. Has a foramen transversarium**