**Core Concept**
Spinal tuberculosis, also known as Pott's disease, is a form of tuberculosis that affects the spine. It is caused by the bacterium *Mycobacterium tuberculosis* and is characterized by the destruction of the vertebral bodies and the intervertebral discs, leading to vertebral collapse and spinal instability.

**Why the Correct Answer is Right**
Exaggerated lumbar lordosis is not a characteristic feature of spinal tuberculosis. In fact, the disease often leads to a loss of lordosis due to vertebral body collapse and spinal instability. The correct answer is incorrect because it suggests a feature that is not typically associated with spinal tuberculosis.

**Why Each Wrong Option is Incorrect**
**Option A:** Back pain is indeed an early symptom of spinal tuberculosis, often presenting as a dull ache or stiffness in the back. This is because the disease process can lead to inflammation and destruction of the vertebral bodies and intervertebral discs.

**Option B:** The dorsolumbar spine is indeed a common site for spinal tuberculosis, particularly in adults. This is because the disease tends to affect the upper and middle regions of the spine, where the vertebral bodies are more prone to destruction.

**Option D:** Spinal tuberculosis can indeed be secondary to lung infection, as *Mycobacterium tuberculosis* can spread from the lungs to the spine through the bloodstream. This is a common mode of transmission for the disease.

**Clinical Pearl / High-Yield Fact**
One key feature of spinal tuberculosis is the presence of an "apple-core" deformity, which is a characteristic radiographic feature of the disease. This deformity is caused by the destruction of the vertebral bodies and intervertebral discs, leading to a rounded or "apple-core" appearance on radiographs.

**✓ Correct Answer: C. Exaggerated lumbar lordosis**