Mostly birds are :-

Options

A. Uricotelic and oviparous
B. Uricotelic and viviparous
C. Ammonotelic and oviparous
D. Uricotelic and ovoviviparous

Answer

To answer the question "Mostly birds are:", we will analyze the options provided and determine which characteristics are most commonly associated with birds.

### Step-by-Step Solution:

1. **Understanding the Characteristics of Birds**:
- Birds are primarily known for their unique adaptations, including their method of reproduction and waste excretion.

2. **Analyzing the First Option: Eurycotalic and Oviparous**:
- **Eurycotalic**: This term refers to organisms that excrete uric acid. Most birds excrete uric acid, which is a characteristic of their physiology.
- **Oviparous**: This term means that organisms lay eggs. Birds reproduce by laying eggs, making this characteristic true for most birds.
- **Conclusion**: This option is correct because it accurately describes the reproductive and excretory traits of most birds.

3. **Analyzing the Second Option: Uricotallic and Viviparous**:
- **Uricotallic**: This part is correct as birds do excrete uric acid.
- **Viviparous**: This term refers to organisms that give birth to live young. Birds do not give birth to live young; they lay eggs.
- **Conclusion**: This option is incorrect due to the viviparous characteristic.

4. **Analyzing the Third Option: Ammonotallic and Oviparous**:
- **Ammonotallic**: This term refers to organisms that excrete ammonia. Birds do not excrete ammonia; they excrete uric acid.
- **Oviparous**: This part is correct as birds lay eggs.
- **Conclusion**: This option is incorrect due to the ammonotallic characteristic.

5. **Analyzing the Fourth Option: Eurekotallic and Ovoviviparous**:
- **Eurekotallic**: This term appears to be a typographical error and is likely meant to refer to uricotallic. However, it is not a standard term.
- **Ovoviviparous**: This term refers to organisms that produce eggs that hatch inside the body. Birds do not exhibit this reproductive strategy.
- **Conclusion**: This option is incorrect due to both characteristics.

6. **Final Conclusion**:
- Based on the analysis, the correct answer is the first option: **Eurycotalic and Oviparous**.