The correct answer is: A. Video board
A video board is a computer expansion card that generates a video signal to be displayed on a monitor or television. It is considered both an input and output device because it receives input from the computer (such as the contents of the video memory) and outputs a video signal to the monitor.
A SCSI host adapter is a device that allows a computer to communicate with SCSI devices, such as hard drives, CD-ROM drives, and scanners. It is considered an input device because it receives data from SCSI devices, but it is not considered an output device because it does not send data to the computer.
The system board CPU is the main processor in a computer. It is responsible for carrying out the instructions of the computer’s programs. It is not considered an input or output device because it does not receive or send data to the computer.
Therefore, the only FRU that is considered both an input and output device is the video board.