What does an arm extended out signify?

Answer: C — Left turn

An arm extended straight out from the driver's side window is a recognized hand signal indicating a left turn. This method of signaling is commonly used by drivers, particularly when their vehicle's turn signals are not functioning. When the arm is fully extended at a horizontal angle, it communicates clearly to other road users that the driver intends to make a left turn. Understanding hand signals is important for safe driving, especially in situations such as riding bicycles or operating vehicles without electronic signals. By using this hand signal, drivers help maintain clear communication on the road, ensuring that other motorists and pedestrians understand their intentions.