Which of the following components is part of a mechanical watch?

A mechanical watch is defined by its operation through a mechanical movement, rather than electronic components. The mechanical movement relies on intricate gears, springs, and other mechanical parts that work together to keep time. This system can be powered either by winding a mainspring or by the motion of the wearer's wrist, in the case of automatic watches.

The presence of a mechanical movement distinguishes these watches from their quartz and digital counterparts, which rely on batteries and electronic circuits to function. Mechanical components are integral to the watch's design, reflecting craftsmanship and traditional watchmaking techniques. This makes the mechanical movement the core element of any mechanical watch.