An example of centrolecithal egg is :

Options

A. Frog
B. Fish
C. Cat
D. Insect

Answer

### Step-by-Step Solution:

1. **Understanding Centrolecithal Eggs**:
- Centrolecithal eggs are characterized by having a large amount of yolk concentrated in the center of the egg, with the nucleus located in the middle. The cytoplasm surrounds the yolk equally.

2. **Identifying Examples**:
- These types of eggs are primarily found in certain groups of organisms, particularly insects.

3. **Analyzing Other Options**:
- **Frog Eggs**: Frog eggs are classified as telolecithal, meaning they have a significant amount of yolk at one end (vegetative pole) and the division occurs at the opposite end (animal pole).
- **Cat Eggs**: Cat eggs are classified as microlecithal, which means they contain a small amount of yolk, leading to a holoblastic cleavage where the division is almost equal but unequal in cell size.
- **Insect Eggs**: Insects exhibit centrolecithal eggs, where the yolk is centrally located, and the cytoplasm is distributed around it.

4. **Conclusion**:
- Based on the definitions and examples discussed, the correct answer for an example of a centrolecithal egg is **insects**.