Layers of an ovum from outside to inside is

Options

A. corona radiata, zona pellucida and vitelline membrane
B. zona pellucida, corona radiata and vitelline membrane
C. vitelline membrane, zona pellucida and corona radiata
D. zona pellucida, vitelline membrane and corona radiata.

Explanation

To answer the question regarding the layers of an ovum from outside to inside, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the innermost layer**: The innermost part of the ovum is the ovum itself, which is also referred to as the egg. This is the primary reproductive cell.

2. **Identify the perivitelline space**: Surrounding the ovum is a space called the perivitelline space. This space is located between the ovum and the next layer.

3. **Identify the zona pellucida**: The next layer outside the perivitelline space is the zona pellucida. This is a thick, transparent layer that surrounds the ovum and is crucial for fertilization.

4. **Identify the outermost layer**: The outermost layer is the corona radiata. This layer consists of a group of cells that provide protection and nourishment to the ovum.

5. **Order the layers from outside to inside**: Now that we have identified all the layers, we can list them in the correct order from outside to inside:
- **Corona Radiata**
- **Zona Pellucida**
- **Perivitelline Space**
- **Ovum (Egg)**

### Final Answer:
The layers of an ovum from outside to inside are:
1. Corona Radiata
2. Zona Pellucida
3. Perivitelline Space
4. Ovum (Egg)

---