Sound box of birds is called

Options

A. pygostyle
B. larynx
C. syrink
D. synsacrum

Explanation

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks for the name of the sound-producing organ in birds, commonly referred to as the "sound box."

2. **Identifying Options**: The options provided are:
- A) Figole style
- B) Larynx
- C) Syrinx
- D) Syn sacrum

3. **Analyzing Each Option**:
- **Figole style**: This is not a recognized term related to bird anatomy. Hence, it is incorrect.
- **Larynx**: This is the sound box in mammals, not birds. Therefore, it is also incorrect.
- **Syrinx**: This is the correct term for the sound-producing organ in birds, located at the junction where the windpipe divides.
- **Syn sacrum**: This is related to the skeletal structure of birds and does not pertain to sound production. Thus, it is incorrect.

4. **Conclusion**: The correct answer is **C) Syrinx**. The syrinx functions without vocal folds and produces sound through the vibrations of the membrana tympaniformis as air flows through it.