The wrist strap is an ESD (electrostatic discharge) prevention tool used to keep the technician and the computer at the same electrical potential so static electricity doesn’t discharge into sensitive components like RAM. Quentin Docter explains that with an antistatic (ESD) wrist strap, you “attach one end to an earth ground… or the computer case and wrap the other end around your wrist. This strap grounds your body and keeps it at a zero charge.” This directly matches option C.

Mike Meyers’ Lab Manual reinforces the same concept: “The secret to avoiding ESD is to keep you and the parts of the computer you touch at the same electrical potential, otherwise known as grounding yourself to the computing device. You can accomplish this by connecting yourself to the computer via… an ESD strap.” In practical terms, RAM and CPU chips are especially ESD-sensitive, so grounding prevents intermittent or catastrophic failures that might occur after installation. Therefore, the purpose of the wrist strap is to ground electrostatic charge.