Which of the following statement is correct?

Options

A. (1) Flatworms exchange Oxygen with carbondioxide by simple diffusion over their entire body surface
B. (2) Larynx is a bony box which help in sound production
C. (3) Epiglottis is made up of collagen fibrous connective tissue
D. (4) in birds larynx is a sound producing organ

Answer

To determine which statement is correct, we will analyze each option one by one.

### Step 1: Analyze Statement A
**Statement A:** Flatworms exchange oxygen with carbon dioxide by simple diffusion over their entire body surface.
- **Analysis:** This statement is true. Flatworms belong to the phylum Platyhelminthes and they do not have specialized respiratory organs. Instead, they rely on diffusion through their body surface to exchange gases. This is effective due to their flat shape, which increases surface area relative to volume.

### Step 2: Analyze Statement B
**Statement B:** Larynx is a bony box which helps in sound production.
- **Analysis:** This statement is false. The larynx is not a bony structure; it is primarily made of cartilage. While it does play a role in sound production, describing it as a "bony box" is incorrect.

### Step 3: Analyze Statement C
**Statement C:** Epiglottis is made up of collagen fibers, connective tissue, fibrous connective tissue.
- **Analysis:** This statement is also false. The epiglottis is primarily composed of elastic cartilage, not collagen fibers or fibrous connective tissue.

### Step 4: Analyze Statement D
**Statement D:** In birds, the larynx is a sound producing organ.
- **Analysis:** This statement is incorrect. In birds, the sound-producing organ is called the syrinx, not the larynx.

### Conclusion
After analyzing all four statements, we find that:
- **Correct Statement:** Statement A is correct: "Flatworms exchange oxygen with carbon dioxide by simple diffusion over their entire body surface."

### Final Answer
The correct statement is **A**.

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