Without teats, mammary glands are found in

Options

A. prototheria
B. metatheria
C. eutheria
D. theria

Answer

To solve the question "Without teats, mammary glands are found in," we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Classification of Mammals**:
- Mammals are classified into different groups. The main class is Mammalia, which is divided into two subclasses: Prototheria and Theria.

2. **Identify the Subclasses**:
- **Prototheria**: This subclass includes egg-laying mammals. The only existing order within this subclass is Monotremata.
- **Theria**: This subclass includes live-bearing mammals and is further divided into two infraclasses: Metatheria (marsupials) and Eutheria (placental mammals).

3. **Examine the Characteristics of Prototheria**:
- One of the key characteristics of Prototheria is that the females lay eggs.
- Another significant feature is that the mammary glands in Prototheria do not have teats (or nipples).

4. **Compare with Theria**:
- In contrast, the subclass Theria (which includes Metatheria and Eutheria) has mammary glands that are equipped with teats.

5. **Conclusion**:
- Based on the characteristics of the subclasses, we conclude that mammary glands without teats are found in the subclass **Prototheria**.

### Final Answer:
The correct answer is **Prototheria**.

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