Which command below will instruct DOS to do a "quick format".

The correct answer is B. FORMAT A: /Q.

The /Q switch tells DOS to perform a quick format. A quick format does not perform a check of the disk for bad sectors, and it does not write a volume label to the disk.

The /QUICK switch is a synonym for the /Q switch.

The /QU switch is not a valid switch.

The /QF switch is not a valid switch.

A quick format is a good option if you are sure that the disk is not damaged and you do not need to write a volume label to the disk.