The correct answer is: B. I/O card
A SCSI host adapter is an I/O card that allows a computer to communicate with SCSI devices. SCSI devices are typically high-speed storage devices such as hard drives, CD-ROM drives, and tape drives.
A CPU is the central processing unit of a computer. It is responsible for carrying out the instructions of a computer program.
A video card is a circuit board that generates the images that are displayed on a computer monitor.
A hard drive is a storage device that stores data on magnetic disks.
None of the above options are correct.