Transmission electron microscope commonly known as TEM and Scanning electron microscope commonly known as SEM are the two types of electron microscope. Electron microscopes make use of electron beam to produce the magnified images of an object. These images can be produced only when object is placed in vacuum. Electronic balance makes use of digital electronic system and is used for weighing purposes and not for image production.
It is the light microscope that produces the images by focusing the light rays on to the object. These rays are then collected by an objective lens.
Hence, the correct answer is option (a) light microscope.