Explanation:

- Option 1: Optics

- Optics is the study of light and its interaction with different materials. It deals with the behavior and properties of light.

- Option 2: Photonics

- Photonics focuses on the generation, manipulation, and detection of photons, mainly in the visible and near-infrared spectrum. It often involves optical fibers.

- Option 3: Astrophysics

- Astrophysics is the branch of astronomy concerned with the physical properties and processes of celestial objects and phenomena.

- Option 4: Acoustics

- Acoustics is the study of sound, including its production, transmission, and effects.