Select one:
a. A specially-designed CD-R drive is necessary for reading data, because the data is recorded in a special format.
b. It is suitable for making a backup copy of data, because the saved data cannot be erased or overwritten.
c. It is capable of high-speed writing by shrinking the recording area of the disc surface.
d. It is suitable as storage for frequently updated large master files, because it has a large storage capacity.