The correct answer is: A. 2400-4700
Floppy disks are a type of magnetic storage medium that was popular in the 1980s and 1990s. They were used to store data on a thin, flexible disk that was enclosed in a plastic case. Floppy disks were typically used to store programs, files, and data.
The speed at which a floppy disk rotates is measured in revolutions per minute (rpm). The general range of speed in revolutions per minute (rpm) at which floppy disks rotate is 2400-4700.
Option B, 390-600, is the speed at which a typical hard drive rotates. Hard drives are a type of magnetic storage medium that is more commonly used today than floppy disks.
Option C, 150-250, is the speed at which a typical CD-ROM rotates. CD-ROMs are a type of optical storage medium that is used to store data and programs.
Option D, 300-600, is the speed at which a typical DVD-ROM rotates. DVD-ROMs are a type of optical storage medium that is used to store data and programs.
Option E, None of the above, is incorrect.