Stop signal (hand signal) which action corresponds?

• A. Left arm straight down, palm facing back.
• B. Left arm extended, palm open.
• C. Left arm raised up, palm open.
• D. Right arm extended.

Answer: (A)

The key idea is that stopping or slowing is shown with a clear, distinct cue that other drivers can read even if you’re not using your brakes. The stop signal is the left arm extended straight down with the palm facing backward. This downward position is unmistakable and stays visible as you slow, helping following riders and drivers understand your intention early. Using the left arm leaves your right hand free for throttle and front brake, and mirrors common signaling practice for riders and bicyclists.

Other signals describe turning motions, which look different from stopping, so they wouldn’t communicate “stop” as clearly. The important habit is to use this downward, left-arm signal to warn others before you slow or stop.