Which device is used for making, breaking, or changing connections in an electrical circuit?

The device used for making, breaking, or changing connections in an electrical circuit is a switch. A switch allows control over the flow of electrical current by either allowing it to pass through when closed or stopping it when open. This functionality is critical in various applications, from simple light switches in homes to more complex circuit designs in electronics.

A battery is primarily a source of electrical energy rather than a component used for controlling the flow of electricity. A diode allows current to flow in one direction only, serving as a component for controlling current flow but not for making or breaking connections in the way a switch does. A resistor is used to reduce the flow of current in a circuit and does not control connections; its primary role is to limit or regulate current based on Ohm's law. Therefore, the correct answer clearly identifies the function of a switch as it pertains to circuit control.