When we sit inside a room, although we do not see the people talking in the same room, we definitely hear their voices. The reason for this is

When we sit inside a room and hear people talking without seeing them, the reason is diffraction (Option D). Diffraction is the bending of sound waves around obstacles and the spreading out of waves when they pass through small openings or gaps. In an enclosed space like a room, sound waves produced by talking people can bend around corners, furniture, and other obstacles. This property of sound waves enables them to reach our ears even when the sound source is not directly visible to us. The wavelength of sound waves is relatively long compared to the size of most obstacles in a room, which enhances their ability to diffract and propagate through the space. As a result, we can clearly hear conversations and other sounds occurring within the same room, regardless of our position relative to the sound source. This characteristic of sound waves is crucial for effective communication and the design of acoustic spaces.