CompTIA Server+

Answer - A - An ESD wrist strap or mat contains a resistor.

Key Takeaway: An ESD wrist strap is a safety device used to channel static electricity to a proper ground when you are handling sensitive computer equipment. Electrostatic discharge can cause device damage when a release of stored static electricity travels from a person’s body into a conductor at a different potential. The ESD wrist strap safely channels the static electricity to a proper ground by bleeding the charge away from you and the computer to a ground source using a resistor.