The membraneous cover of the ovum at ovulation is:

Options

A. corona radiata
B. zona radiata
C. zona pellucida
D. chorion

Explanation

**Step-by-Step Solution:**

1. **Identify the Question**: The question asks about the membranous cover of the ovum at the time of ovulation.

2. **Understand the Structure of the Ovum**: The ovum has several layers surrounding it. The question specifically refers to the outermost layer.

3. **Determine the Outermost Layer**: The outermost layer of the ovum is known as the **corona radiata**. This layer is crucial as it provides protection and nourishment to the ovum.

4. **Formation of the Corona Radiata**: The corona radiata is formed from the **follicular cells**. These cells are derived from the ovarian follicles and play a significant role in the development of the ovum.

5. **Identify the Inner Layer**: Beneath the corona radiata, there is another layer called the **zona pellucida**. This layer is important for the fertilization process as it surrounds the ovum.

6. **Conclusion**: Therefore, the membranous cover of the ovum at ovulation is the **corona radiata**, with the zona pellucida lying just beneath it.

**Final Answer**: The membranous cover of the ovum at ovulation is the **corona radiata**.

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