Which Unity component is used to change the appearance of GameObjects by controlling light interaction?

The correct choice for changing the appearance of GameObjects by controlling light interaction is the Material.

A Material in Unity acts as a container for shaders and textures, essentially determining how the surface of a GameObject interacts with light. It defines properties such as color, transparency, reflection, and lighting response on the surface of a 3D object. By applying different materials to a GameObject, you can achieve varied visual effects, such as shiny surfaces, matte finishes, and other complex interactions with light. This flexibility allows artists and developers to create visually appealing environments and objects that respond realistically to lighting conditions in the scene.

While shaders are crucial as they dictate how the rendering of the object is processed, they rely on materials to be effectively utilized on GameObjects. Textures provide images that can be mapped onto materials to add detail, but alone they do not control how light interacts with the surface. The MeshFilter is a component that defines the shape of a GameObject by referring to a Mesh, but it does not have any influence on how the GameObject interacts with light. Hence, the Material is the primary component responsible for altering a GameObject's appearance through light interaction.