Synovial joint is :

Options

A. Pivot joint
B. Fibrous joint
C. Ball and socket joint
D. All of these

Answer

### Step-by-Step Solution:

1. **Definition of Synovial Joint**: A synovial joint is a type of joint found between bones that allows for movement. These joints are characterized by a fluid-filled joint cavity that enables the bones to move against each other smoothly.

2. **Identifying Joint Types**:
- The question provides several options for types of joints. We need to identify which of these is a synovial joint.

3. **Analyzing the Options**:
- **Option 1: Pivot Joint**: This joint allows for rotational movement and is found between the first and second vertebrae (atlas and axis). While it is a type of joint, it is not classified as a synovial joint.
- **Option 2: Fibrous Joint**: These joints are immovable and are found in the skull. They are not synovial joints.
- **Option 3: Ball and Socket Joint**: This is a type of synovial joint where the rounded surface of one bone fits into the cup-like depression of another bone, allowing for a wide range of movement.
- **Option 4: All of these**: This option suggests that all previous options are synovial joints, which is incorrect.

4. **Conclusion**: After analyzing the options, the correct answer is **Option 3: Ball and Socket Joint**, as it is indeed a type of synovial joint.