Which of the following is suitable as a description of the characteristics of MO?
a) Data is recorded by irradiating laser light on a recording medium covered with a magnetized recording film, thereby heating it and simultaneously changing the direction of magnetization.
b) Data is recorded on a thin plastic disk with a magnetic coating simply by changing the magnetization polarity.
c) Data is recorded by a combination of extremely small depressed areas called pits, and flat regions called lands which are between the pits.
d) Data is recorded using phase changes of a recording film being crystallized and uncrystallized by irradiating a laser light.