Croaking of Frog is

Options

A. hunger call
B. sex call for female
C. danger call
D. musical note

Answer

### Step-by-Step Solution:

1. **Understanding Croaking**: Croaking is a sound produced by frogs, primarily by male frogs, as a means of communication.

2. **Vocal Mechanism**: Frogs have vocal cords similar to humans, but they also possess a vocal sac. This sac acts as an amplifier for the sounds they produce.

3. **Process of Croaking**:
- The frog begins by inhaling air.
- It then closes its nostrils.
- The air is forced back and forth between the lungs and the vocal sac.
- This movement causes the vocal cords to vibrate, producing sound.

4. **Purpose of Croaking**: The primary purpose of croaking in male frogs is to attract female frogs for mating. This is known as a mating call.

5. **Types of Calls**: The calls can vary in complexity, ranging from simple clicks to more complex sounds like whistles or long songs.

6. **Conclusion**: Given the context and purpose of the croaking sound, the correct answer to the question "Croaking of Frog is" is **sex call for female**.