A deltoid ridge occurs in

Options

A. radius
B. ulna
C. femur
D. humerus

Explanation

To answer the question "A deltoid ridge occurs in," we will follow these steps:

### Step-by-Step Solution:

1. **Identify the Bones Listed**: The question provides four options: radius, ulna, femur, and humerus. All of these are long bones in the human body.

2. **Understand the Location of Each Bone**:
- **Radius**: Located in the forearm, on the thumb side.
- **Ulna**: Also located in the forearm, on the side opposite the thumb.
- **Femur**: The longest and strongest bone in the body, located in the thigh.
- **Humerus**: The bone of the upper arm that connects the shoulder to the elbow.

3. **Define Deltoid Ridge**: The deltoid ridge is a specific anatomical feature that is a ridge-like structure on a bone.

4. **Locate the Deltoid Ridge**: The deltoid ridge is found on the humerus. It serves as an attachment point for the deltoid muscle, which is responsible for arm abduction.

5. **Conclusion**: Since the deltoid ridge is specifically associated with the humerus, the correct answer to the question is the **humerus**.

### Final Answer:
A deltoid ridge occurs in the **humerus**.

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