The window which projects outside a room of a building for admitting more light and air, is known A. Bay window B. Casement window C. Lantern window D. Dormer window

The correct answer is: A. Bay window.

A bay window is a window that projects outward from the wall of a building, creating a three-sided extension. It is typically made up of three or more windows that are joined together, and it can be either square or rectangular in shape. Bay windows are often used to add light and air to a room, and they can also be used to create a more interesting and inviting space.

Here is a brief description of each option:

• A casement window is a window that opens and closes by swinging on hinges. It is typically made of wood or metal, and it can be either single- or double-hung. Casement windows are often used in older homes, and they can be a good choice for adding ventilation to a room.
• A lantern window is a small, circular window that is typically located in the roof of a building. It is often used to provide light and ventilation to an attic or loft space.
• A dormer window is a small window that projects from the sloping roof of a building. It is typically used to provide light and ventilation to a room that is located under the roof.

I hope this helps!