The correct answer is: B. Semiconductor laser.
A semiconductor laser is a type of laser that uses a semiconductor as its active medium. Semiconductor lasers are typically used in optical communication, optical storage, and laser printing.
A dye laser is a type of laser that uses a dye as its active medium. Dye lasers are typically used in spectroscopy, medical applications, and laser printing.
An excimer laser is a type of laser that uses an excimer as its active medium. Excimer lasers are typically used in semiconductor manufacturing, material processing, and laser surgery.
A gas laser is a type of laser that uses a gas as its active medium. Gas lasers are typically used in spectroscopy, telecommunications, and laser surgery.
In a laser printer, a semiconductor laser is used to create an image on a drum. The image is then transferred to paper using a toner cartridge. The toner is then fused to the paper using heat and pressure.
Semiconductor lasers are used in laser printers because they are small, efficient, and reliable. They are also relatively inexpensive to manufacture.