The correct answer is: A. MODE COLOUR

The MODE command is used to configure the display settings of a computer. The COLOUR subcommand is used to specify the color display, 40 columns and color.

The syntax for the MODE COLOUR command is:

MODE COLOUR [B|C] [n] [m]

Where:

  • B or C specifies the type of display: B for monochrome, C for color.
  • n is the number of columns.
  • m is the color number.

For example, to configure a color display with 40 columns and color number 10, you would use the following command:

MODE COLOUR C 40 10

The MODE/C command is used to change the screen mode. The CO40 command is not a valid command. The MODE CHANGE command is not a valid command.