Select the correct match out of the following.

Options

A. Floating ribs - `11^(th) and 12^(th)` pairs of ribs
B. Vertebrae of backbone - Joined by freely movable joints
C. Liquid endoskeleton - Snake
D. Fixed joint - Lower jaw of the skull

Explanation

**Step-by-Step Solution:**

1. **Identify the Options**: The question asks to select the correct match from a list of options related to body movements and skeletal structures.

2. **Analyze the First Option**: The first option states that "floating ribs are the 11th and 12th pair of ribs."
- **Explanation**: Floating ribs are indeed the 11th and 12th pairs of ribs. They are called floating ribs because they are not directly attached to the sternum (breastbone) but are attached to the vertebrae at the back. This makes this option correct.

3. **Analyze the Second Option**: The second option claims that "the vertebrae of the backbone are joined by a freely movable joint."
- **Explanation**: This is incorrect because the joints between vertebrae are not freely movable; they allow slight movement, making them slightly movable joints, not freely movable joints.

4. **Analyze the Third Option**: The third option states that "liquid endoskeletons are found in snakes."
- **Explanation**: This is also incorrect. Liquid endoskeletons are typically found in lower organisms like jellyfish, not in snakes, which have a bony skeleton.

5. **Analyze the Fourth Option**: The fourth option states that "the lower jaw of the skull is a fixed joint."
- **Explanation**: This is incorrect. The lower jaw (mandible) is a movable joint, while the upper part of the skull has fixed joints.

6. **Conclusion**: After analyzing all the options, the only correct match is the first option regarding floating ribs.

**Final Answer**: The correct match is the first option: "Floating ribs are the 11th and 12th pair of ribs."

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