Four of the following five are alike in a certain way and so form a group. Which is the one that does not belong to that group?

The answer is C. Break.

A clutch, wheel, gear, and car are all mechanical components. A clutch is a device that connects and disconnects the engine to the transmission. A wheel is a circular object that rotates around an axle. A gear is a toothed wheel that meshes with another gear to transmit power. A car is a vehicle that is powered by an engine and has four wheels.

A break is not a mechanical component. It is a verb that means to stop something from moving.