Which action should a driver take if their turn signal is not functioning?

Answer: B — Use hand signals

Using hand signals is the appropriate action for a driver whose turn signal is not functioning. Hand signals are a universally recognized method to communicate a driver's intention to other road users, particularly when a vehicle's turn signal lights are inoperable. By using a hand signal, the driver can effectively indicate whether they are planning to turn left, turn right, or stop, thereby promoting safe driving practices and reducing the risk of accidents caused by miscommunication. Driving cautiously without signaling does not effectively communicate the driver's intentions, which could lead to confusion for other drivers. Making turns only when there are no other vehicles around does not address the issue of signaling and could still result in unsafe situations. Calling for roadside assistance may be warranted for other mechanical issues but is not necessary for a malfunctioning turn signal when a hand signal can suffice. Therefore, using hand signals ensures proper communication on the road, maintaining safety for all drivers.