Which of the following is a blank optical disk where you can save only once, even while the whole
space available is not used?

A.
CD-MO

B.
CD-ROM

C.
CD-R

D.
CD-RW

Explanation:
A Compact Disc-Recordable (CD-R) is a variant of the Compact Disc made-up by Philips and Sony. CDR is a Write Once Read Many (WORM) optical medium, although the complete disk does not have to
be fully written in the same session. CD-R preserves a high level of compatibility with the standard
CD readers; in contrast to the CD-RW that can be re-written, CD-RW is not competent of playing on
numerous readers and also exploits more expensive media.

B is incorrect. A Compact disc read-only medium (CD-ROM) is a pre-pressed compact disc
that holds data accessible to, but
not writable by a computer for data storage and music playback.

D is incorrect. A CD-RW (Compact Disc-ReWritable) is a rewritable optical disc. It was
introduced in 1997 and was called “CDWritable” during the development. It was preceded by the CD-MO that was not commercially
released.

A is incorrect. CD-MO is a standard for magneto-optical recordable and erasable CDs
introduced in 1990 before the
introduction of the CD-RW technology. It was a CD with a magneto-optical recording layer. The CDMO standard also permitted for an
optional non-erasable zone on the disk that could be read by common CD-ROM reader units.