The correct answer is (d). Laser is a device for producing stimulated radiation.
Spontaneous radiation is radiation that is emitted by an atom or molecule without any external stimulus. Dispersed radiation is radiation that is spread out over a wide range of frequencies. Scattered radiation is radiation that is redirected by interaction with matter.
Lasers produce light by stimulating atoms or molecules to emit light in a coherent manner. This means that the light waves produced by a laser are all in phase with each other, which gives laser light its characteristic properties, such as its high brightness and its ability to be focused into a very small spot.
Lasers are used in a wide variety of applications, including surgery, telecommunications, and manufacturing.