In cockroach the audioreceptors are situated on :

Options

A. On legs
B. Antenna
C. Sensory receptor
D. Anal cerci

Answer

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks where the audioreceptors are located in a cockroach. Audioreceptors are sensory structures that detect sound or vibrations.

2. **Analyzing the Options**: The options provided are:
- Legs
- Antenna
- Sensory receptor
- Annulus oocy

3. **Identifying the Correct Structure**:
- **Legs**: While legs are important for movement, they do not have audioreceptors.
- **Antenna**: Antennae are sensory organs, but they are primarily used for smell and touch, not for detecting sound.
- **Sensory receptor**: This is a general term and does not specify a location.
- **Annulus oocy**: This refers to the anal cerci, which are two small appendages located at the rear end of the cockroach.

4. **Understanding the Function of Annulus Oocy**: The annulus oocy (or anal cerci) are equipped with sensory hairs that function as motion detectors. They can detect slight movements and changes in air pressure, which can indicate the presence of predators or other threats.

5. **Conclusion**: Based on the analysis, the correct answer is that the audioreceptors in cockroaches are situated on the annulus oocy (anal cerci).

### Final Answer:
In cockroach, the audioreceptors are situated on the annulus oocy.

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