Which hand signal is used to indicate to stop?

The hand signal used to indicate a stop is the left arm positioned downward with the palm facing the rear. This signal is commonly recognized by drivers and is essential for communicating with other road users when a vehicle intends to stop. It effectively conveys the driver's intent to halt their vehicle, ensuring safety on the road by alerting drivers behind them.

In contrast, the other options represent different signals: raising the left arm indicates a right turn, while bending the left arm at a 90-degree angle signifies a left turn. The right arm bent at a 90-degree angle is also used to signal a right turn. Understanding these signals is crucial for promoting clear communication among drivers and ensuring adherence to traffic regulations.