Explanation:
The answer is A. Vibraphones.
strings is the family that includes violins, cellos, guitars, etc.
brass includes trumpets and the tuba, etc.
percussion includes drums, tambourines, etc.
A competing device is the Camera Lucida . "Camera Obscura" means "dark room", and the use of a pinhole in a window blind to form an inverted image of an outside scene on an opposite wall of a dark room.
