Intercostal muscles are found in

Options

A. Fingers
B. Thoracic ribs
C. Femur
D. Radius-ulna

Explanation

**Step-by-Step Solution:**

1. **Understanding Intercostal Muscles**: Intercostal muscles are a group of muscles located between the ribs. They play a crucial role in the respiratory process.

2. **Origin and Insertion**: The intercostal muscles originate from the first rib and extend down to the eleventh rib. Their insertion points are from the second rib to the twelfth rib.

3. **Identifying the Location**: The question asks where intercostal muscles are found. The options provided include fingers, thoracic ribs, femur, and radius or ulna.

4. **Analyzing the Options**:
- **Fingers**: This option is incorrect as intercostal muscles are not located in the fingers.
- **Thoracic Ribs**: This option is correct as intercostal muscles are specifically located between the ribs in the thoracic region.
- **Femur**: This is the longest bone in the thigh and does not contain intercostal muscles.
- **Radius or Ulna**: These are bones in the forearm and do not involve intercostal muscles.

5. **Conclusion**: Based on the analysis, the correct answer is that intercostal muscles are found in the thoracic ribs.

**Final Answer**: Intercostal muscles are found in the thoracic ribs.

---