Which of the following is not an optical storage device?

Concept

Storage devices are classified by the physical mechanism used to record and retrieve data. Optical media use a laser to read or write data on a disc, whereas semiconductor memory stores bits in electronic circuits.

Application

Apply the storage mechanism to each offered value:

• CD-ROM stores read-only data on a compact disc and is read optically with a laser.

• DVD-ROM stores read-only data on a digital versatile disc and is read optically with a laser.

• RAM stores working data in semiconductor memory cells and is accessed electronically, not through an optical disc.

• CD-R records data once on a compact disc and uses an optical laser for writing and reading.

Cross-check

Grouping the media by mechanism places CD-ROM, DVD-ROM, and CD-R in the laser-read disc group, while RAM remains in the semiconductor-memory group.

Therefore, RAM is not an optical storage device.