Which of the following act as a brain in cockroach ?

Options

A. Suprapharyngeal ganglion
B. Supraoesophageal ganglion
C. Ventral never cord
D. Segmental ganglion

Answer

To determine which structure acts as the brain in a cockroach, we need to analyze the provided options:

1. **Suprafarangial Ganglion**: This structure is primarily associated with earthworms and is not relevant to cockroaches. It is involved in spontaneous alterations and negative movements in earthworms. Thus, this option is incorrect.

2. **Supraesophageal Ganglion**: This ganglion is recognized as the brain of arthropods, including cockroaches. It is located above the esophagus and is responsible for processing sensory information and coordinating responses. Therefore, this option is likely correct.

3. **Ventral Nerve Cord**: This is a long cord of nervous tissue that runs along the length of the animal's body. It is not considered a brain but rather a part of the nervous system that connects various ganglia. Hence, this option is incorrect.

4. **Segmental Ganglion**: These ganglia are found in both annelids and arthropods and are part of the segmented ventral nerve cord. While they play a role in the nervous system, they do not function as the brain. Thus, this option is also incorrect.

Based on this analysis, the correct answer is **Supraesophageal Ganglion**, as it serves as the brain in cockroaches.

### Summary of Steps:
1. Identify the options provided.
2. Analyze each option to determine its relevance to the cockroach.
3. Conclude that the **Supraesophageal Ganglion** acts as the brain in cockroaches.