Which one of the following is a flat bone on the ventral midline of thorax ?

Options

A. vertebra
B. sternum
C. ribs
D. hyoid

Answer

To solve the question "Which one of the following is a flat bone on the ventral midline of the thorax?", we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Question**: We need to identify a flat bone located on the ventral (front) midline of the thorax (chest area).

2. **Analyze the Options**:
- **Option 1: Vertebra** - Vertebrae are small bones that make up the backbone. They are not flat bones and are not located in the thorax's ventral midline.
- **Option 2: Sternum** - The sternum, commonly known as the breastbone, is a flat bone located in the center of the chest, making it the correct answer.
- **Option 3: Ribs** - Ribs are curved bones that form the rib cage around the thoracic cavity. They are not flat bones and do not lie on the ventral midline.
- **Option 4: Hyoid Bone** - The hyoid is a horseshoe-shaped bone located in the neck, not in the thorax.

3. **Identify the Correct Answer**: Based on the analysis, the only flat bone located on the ventral midline of the thorax is the **sternum**.

4. **Conclusion**: Therefore, the correct answer is **Option 2: Sternum**.