A driver ready to make a left turn when the signal light turns green should:

When making a left turn at a green signal light, the driver must prioritize safety and assess the surrounding traffic conditions. The correct choice emphasizes the importance of ensuring that oncoming traffic does not pose a danger before proceeding with the turn. This involves carefully checking for any vehicles heading straight through the intersection, as they may be traveling at higher speeds or may not be expecting your turn.

Additionally, the driver should signal intention to indicate that a left turn is forthcoming, which helps communicate with other road users and enhances safety at the intersection. Failing to ensure that oncoming traffic does not constitute a hazard can lead to accidents.

In contrast to this choice, quickly turning before oncoming traffic becomes a factor disregards safety, while simply signaling and making the turn without assessing traffic could lead to potential conflicts. Turning from the lane closest to the right side may not be relevant to the situation at all, as drivers should turn from the appropriate lane as indicated by road markings, ensuring compliance with traffic laws. The broader principle at play is the responsibility of drivers to be observant and cautious when navigating intersections, making safety the priority during maneuvers such as a left turn.