What safety device is commonly worn to prevent ESD?

The wrist strap is the correct answer because it is specifically designed to prevent electrostatic discharge (ESD), which can damage sensitive electronic components. The wrist strap is typically made of a conductive material that safely grounds any static electricity that may build up on a person's body. By wearing a wrist strap connected to a grounded surface or equipment, the risk of ESD is significantly reduced, making it an essential safety device in environments where electronic components are handled.

In contrast, hard hats are primarily used for protection against head injuries from falling objects or impacts, making them unsuitable for ESD protection. Safety goggles protect the eyes from hazards such as flying debris or chemicals but do not address electrostatic risks. Ear plugs are designed to protect hearing in loud environments and have no relation to electrical safety. Thus, the wrist strap stands out as the critical device for ESD prevention in electronics handling and maintenance scenarios.