Which of the following have relatively more complex nervous system

Options

A. first triploblastic animals
B. first segmented worms
C. the largest group of animals
D. pseudo coelomate animals

Answer

To determine which of the following options has a relatively more complex nervous system, we can analyze the characteristics of each option provided.

### Step-by-Step Solution:

1. **Understand the Definition of a Complex Nervous System**:
- A complex nervous system is typically found in higher animals, particularly in mammals and other vertebrates. It includes a well-developed brain and spinal cord, along with a network of nerves.

2. **Identify the Options**:
- The options given in the question are:
- A) Tripoblastic animals
- B) Segmented worms
- C) Largest group of animals
- D) Pseudocoelomate animals

3. **Analyze Each Option**:
- **A) Tripoblastic Animals**:
- Tripoblastic animals have three germ layers (ectoderm, mesoderm, endoderm). They can include both simple and complex organisms, but many do not have a complex nervous system.
- **B) Segmented Worms**:
- Segmented worms (like earthworms) have a nervous system that includes ganglia and nerve cords, but they are still considered invertebrates and do not have a highly complex nervous system compared to vertebrates.
- **C) Largest Group of Animals**:
- This option refers to vertebrates, particularly mammals, which possess a highly developed and complex nervous system.
- **D) Pseudocoelomate Animals**:
- Pseudocoelomate animals (like roundworms) have a simpler nervous system and are also invertebrates.

4. **Conclusion**:
- Based on the analysis, the option that represents animals with a relatively more complex nervous system is **C) Largest group of animals**.

### Final Answer:
- The correct answer is **C) Largest group of animals**.