Final answer:
The first action a driver should take before making a turn is to signal at least 100 feet before the turn. This allows other road users to anticipate the driver's actions and ensures safety on the road. The driver should also slow down and, if required, stop the vehicle before executing the turn.
Step-by-step explanation:
The first thing a driver should do after deciding to make a turn is signal at least 100 feet from the turn. Signaling before a turn is critical for safety reasons; it alerts other drivers and pedestrians of your intentions to change direction. Once the signal is on, the driver should also assess the traffic conditions, including the speed and proximity of surrounding vehicles, and slow down to make the turn safely.
It is crucial to perform these actions well in advance to provide enough time for others to react accordingly. Putting down any electronic devices and stopping when necessary are also essential but are subsequent steps after the initial turn signal.
This allows other drivers to anticipate the driver's intentions and adjust their driving accordingly. Signaling is a crucial step in ensuring safe and efficient traffic flow.
Therefore the correct Option is D. signal at least 100 feet from turn.