You are installing a hard drive into a desktop PC. The best way to connect the hard drive on a modern client that will be used in an office setting for word processing and running an online email client would be via:
While all of the answers are valid methods of connecting a hard drive, SATA is the most preferred method on a client PC in the constraints of the question.
This is due to SATA most closely matching the throughput requirements of a client PC, being a modern storage connector, and not requiring additional adapters for buses that may not be present on a modern motherboard.
Hard disk drives are accessed over one of a number of bus types, including parallel ATA (PATA, also called IDE or EIDE; described before the introduction of SATA as ATA), Serial ATA (SATA), SCSI, Serial Attached SCSI (SAS), and Fibre Channel. Bridge circuitry is sometimes used to connect hard disk drives to buses with which they cannot communicate natively, such as IEEE 1394, USB, SCSI and …