What action should be taken when you wish to signal for a left turn?

To signal a left turn, the appropriate action is to hold your left arm straight out. This hand signal is universally recognized as the indication for a left turn when driving. It provides a clear and visible communication to other drivers and pedestrians about your intended direction. By extending your left arm parallel to the ground, you ensure that your signal is easily seen, which is crucial for safety, especially in situations where turn signals may not be functioning or visible.

The other options do not convey the correct message for a left turn. For example, raising the right arm is not a standard signal and could cause confusion, as it does not indicate a left turn. Similarly, holding your left arm at a 90-degree angle typically signals a right turn, not a left. Waving your hand does not serve as a reliable or clear signal for any specific turn and could be misinterpreted by other road users. Therefore, the clear and effective way to signal a left turn is by extending your left arm straight out.