In prototherians mammary glands are

Options

A. Absent
B. Present in male only
C. Present in female only
D. Present in male and female both

Answer

### Step-by-Step Solution:

1. **Understanding Prototherians**:
- Prototherians are a group of mammals known as egg-laying mammals. They are distinct from other mammals because they lay eggs instead of giving live birth.

2. **Characteristics of Prototherians**:
- These mammals possess mammary glands, which are essential for nourishing their young ones after they hatch from the eggs.

3. **Examples of Prototherians**:
- A well-known example of a prototherian is the platypus. It's important to note that many members of this group are now extinct.

4. **Mammary Glands in Prototherians**:
- In prototherians, mammary glands are present in both males and females. This is a unique characteristic of this group compared to most other mammals, where mammary glands are typically found only in females.

5. **Analyzing the Options**:
- Option A: Mammary glands are absent - This is incorrect.
- Option B: Mammary glands are present in males only - This is also incorrect.
- Option C: Mammary glands are present in females only - This is incorrect as well.
- Option D: Mammary glands are present in both males and females - This is the correct answer.

6. **Conclusion**:
- Therefore, the correct answer to the question is that in prototherians, mammary glands are present in both males and females.

### Final Answer:
**D: Present in male and female both.**

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