What tool is commonly used to tighten or loosen bolts?

The correct choice is the wrench, which is specifically designed to grip and turn nuts and bolts. Wrenches come in various forms, such as open-end, box-end, adjustable, and torque wrenches, each tailored for different applications and sizes of fasteners. Their design allows for a secure hold on the fastener, providing the necessary leverage to tighten or loosen it effectively.

Other tools like screwdrivers and pliers have different functions; screwdrivers are mainly used for driving screws rather than bolts, while pliers can grip various objects but do not effectively apply enough torque to work with bolts securely. A socket set can also be used for bolts, as it includes a ratchet and various socket sizes, yet it is a more complex tool comprising multiple pieces and might not be as universally accessible for quick tasks as a simple wrench. Therefore, while both the socket set and the wrench can perform the task, the wrench is the most straightforward and commonly recognized tool for tightening or loosening bolts.