Which of the following bones is not a cranial bone?

Options

A. Frontal bone
B. Occipital bone
C. Zygomatic bone
D. Sphenoid bone

Answer

To determine which of the following bones is not a cranial bone, we need to identify the bones that make up the human skull and categorize them into cranial and facial bones.

### Step-by-Step Solution:

1. **Understand the Structure of the Skull**:
- The human skull is composed of two sets of bones: cranial bones and facial bones.
- There are a total of 22 bones in the skull, which includes 8 cranial bones and 14 facial bones.

2. **Identify the Cranial Bones**:
- The cranial bones in the human skull include:
- 1 Ethmoid bone
- 1 Frontal bone
- 1 Occipital bone
- 2 Parietal bones
- 1 Sphenoid bone
- 2 Temporal bones

3. **List the Options Given**:
- The options provided are:
- A) Frontal bone
- B) Occipital bone
- C) Zygomatic bone
- D) Sphenoid bone

4. **Analyze Each Option**:
- **Frontal Bone**: This is a cranial bone.
- **Occipital Bone**: This is also a cranial bone.
- **Sphenoid Bone**: This is a cranial bone as well.
- **Zygomatic Bone**: This is not a cranial bone; it is classified as a facial bone.

5. **Conclusion**:
- The only bone from the options that is not a cranial bone is the **Zygomatic bone**.

### Final Answer:
The bone that is not a cranial bone is the **Zygomatic bone**.