Which of the following is a correct match between a vertebra and its characteristic feature which helps in its identification?

Options

A. Atlas - Has odontoid peg
B. Thoracic vertebrae - 12 pairs
C. Lumbar vertebrae - Centra have articulation facets for ribs
D. Vertebra prominens (7th cervical vertebra) - Undivided spinous process with tubercle at the tip

Answer

To solve the question regarding the correct match between a vertebra and its characteristic feature, let's analyze each option step by step.

### Step-by-Step Solution:

1. **Understanding the Options**:
- **Option A**: Atlas has odontoid process.
- **Option B**: Thoracic vertebrae which are 12 pairs.
- **Option C**: Lumbar vertebrae have centra with articulation facets for ribs.
- **Option D**: The seventh cervical vertebra has an undivided spinous process with a tubercle.

2. **Evaluating Option A**:
- The atlas (C1 vertebra) does not have an odontoid process; this feature is characteristic of the axis (C2 vertebra). Therefore, this option is incorrect.

3. **Evaluating Option B**:
- Thoracic vertebrae are indeed 12 in number, but they are not referred to as "12 pairs." The term "pairs" is misleading as it usually refers to ribs. Hence, this option is also incorrect.

4. **Evaluating Option C**:
- Lumbar vertebrae do not have articulation facets for ribs. Instead, thoracic vertebrae have these facets for rib articulation. Therefore, this option is incorrect.

5. **Evaluating Option D**:
- The seventh cervical vertebra (C7) is known as the vertebra prominens and has a prominent spinous process, which is typically not divided and does not have a tubercle. Thus, this option is also incorrect.

6. **Conclusion**:
- After evaluating all the options, none of the provided options are correct. However, if we consider the context of the question and the characteristics of vertebrae, the closest correct identification feature is that the lumbar vertebrae are characterized by their large size and lack of rib articulation, while the thoracic vertebrae articulate with ribs.

### Final Answer:
None of the options provided are correct as stated. However, the correct identification feature for lumbar vertebrae is that they do not articulate with ribs.