Which of the following does not use an internal combustion enginea. a cannonb. a lawnmowerc. a windmilld. a car

c) a Windmill

Explanation:

A lawn mower may have a two stroke or a 4 stroke internal combustion engine.

Wind mill is a device that runs with wind. When wind blows, wings of the wind mill rotate. Wind mills are used to generate electricity. It is a renewable source of energy that requires large farms or open space for their establishment and maintenance.

In a cannon gun powder is ignited ,  not with the help of an engine , but a different method for its ignition.