[A] : Accomodation in the bird's eye is con- trolled by the ciliary apparatus.
[R]: It involves deformation of retina.

Options

A. If both A and R are true and R is the correct explanation of A
B. If both A and R are true but R is not the correct explanation of A
C. If A is true and R is false
D. If both A and R are false

Answer

**Step-by-Step Solution:**

1. **Understanding Accommodation**:
- Accommodation is the process by which the eye adjusts its optical power to focus on objects at different distances. This is crucial for clear vision.

2. **Role of the Ciliary Apparatus**:
- In birds, as well as in other vertebrates, the ciliary apparatus (or ciliary body) plays a key role in accommodation. It contains muscles that control the shape of the lens. When these muscles contract or relax, they change the curvature of the lens, allowing the eye to focus light properly on the retina.

3. **Function of the Retina**:
- The retina is the light-sensitive layer at the back of the eye where images are formed. For clear vision, light must be focused on the retina. If the light does not fall on the retina correctly, vision will be impaired.

4. **Evaluating the Statements**:
- Statement [A]: "Accommodation in the bird's eye is controlled by the ciliary apparatus."
- This statement is true because the ciliary muscles adjust the lens shape for focusing.
- Statement [R]: "It involves deformation of the retina."
- This statement is false. Accommodation does not involve the deformation of the retina; rather, it is about adjusting the lens to focus light correctly on the retina.

5. **Conclusion**:
- Therefore, we conclude that statement [A] is true and statement [R] is false.