If a driver is signaling by extending their arm straight down, what action are they indicating?

Answer: A — Stopping

When a driver extends their arm straight down while signaling, they are indicating that they intend to stop their vehicle. This hand signal is a clear and universally recognized method for communicating to other road users their intention to reduce speed or come to a complete stop. The straight down position of the arm is especially important in situations where the vehicle's turn signals might not be visible, such as when a driver is not in a large vehicle or when visibility is obstructed. Proper use of hand signals, including this one for stopping, is crucial for ensuring the safety of all road users by providing clear communication about a driver's intentions. Other signals, such as extending the arm horizontally typically indicate a left turn, while an upward arm signal typically indicates a right turn. Thus, understanding these signals helps to promote a safer driving environment.