Mark the correct one

Options

A. Labeo-internal fertlization
B. Frog-internal fertilization
C. Birds-external fertilization
D. Balaenoptera-Internal fertilization

Answer

To solve the question, we need to analyze each option regarding the type of fertilization that occurs in the respective organisms.

### Step-by-Step Solution:

1. **Understand the Types of Fertilization**:
- Internal Fertilization: This occurs when the sperm fertilizes the egg inside the female's body.
- External Fertilization: This occurs when the sperm and egg unite outside the female's body.

2. **Evaluate Option A: Labio - Internal Fertilization**:
- The term "Labio" likely refers to "Labeo," which is a genus of fish. Fish typically exhibit external fertilization.
- **Conclusion**: This option is incorrect.

3. **Evaluate Option B: Frog - Internal Fertilization**:
- Frogs are amphibians, and they usually reproduce through external fertilization, where eggs are laid in water and fertilized externally.
- **Conclusion**: This option is incorrect.

4. **Evaluate Option C: Birds - External Fertilization**:
- Birds generally exhibit internal fertilization, where the male fertilizes the eggs inside the female before they are laid.
- **Conclusion**: This option is incorrect.

5. **Evaluate Option D: Balenoptera - Internal Fertilization**:
- Balenoptera refers to a genus of whales, which are mammals. Mammals typically reproduce through internal fertilization.
- **Conclusion**: This option is correct.

### Final Answer:
The correct option is **D. Balenoptera - Internal Fertilization**.

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