Which component is a lever used to turn a rudder to steer a boat?

The correct answer is the tiller, as it is the component that acts as a lever to control the rudder and steer the boat. When a boater moves the tiller, it pivots, which in turn moves the rudder from side to side. This movement alters the direction of the boat. The tiller is typically a simple stick or arm attached directly to the rudder, allowing for direct manipulation by the helmsman.

In contrast, an impeller is a device that pumps water, often used in cooling systems or for propulsion in some types of boats, but it has no steering function. A halyard is a rope used to raise or lower sails, and while it plays a crucial role in sailing, it is not involved in steering. The drive shaft is part of the propulsion system that connects the engine to the propeller, facilitating movement through water but does not have any direct effect on steering the vessel.