**Core Concept**
The primary curvatures of the vertebral column are two normal, fixed curvatures present in the human spine from birth, which are the thoracic kyphosis and the sacral lordosis. These curvatures are essential for maintaining posture and facilitating movement.

**Why the Correct Answer is Right**
The thoracic kyphosis is a concave anterior curvature of the thoracic spine due to the shape of the vertebral bodies and the ribs. This curvature is a result of the larger anterior vertebral body height compared to the posterior height. The sacral lordosis is a concave posterior curvature of the sacrum, which is a result of the wedge-shaped sacral vertebrae. These primary curvatures are present from birth and remain unchanged throughout life.

**Why Each Wrong Option is Incorrect**
**Option A:** Lumbar lordosis is a secondary curvature, not a primary curvature.
**Option B:** Cervical lordosis is a secondary curvature, not a primary curvature.
**Option C:** Lumbar kyphosis is a pathologic curvature, not a primary curvature.

**Clinical Pearl / High-Yield Fact**
It's essential to remember that the primary curvatures of the vertebral column are present from birth and remain unchanged throughout life, while secondary curvatures can be influenced by various factors such as posture, muscle imbalances, and degenerative changes.

**Correct Answer:** C. Thoracic kyphosis and sacral lordosis.