In addition to checking the left side mirror, where else should a driver look before leaving a curve?

Looking over the left shoulder is essential for a driver before leaving a curve, as it allows them to check for vehicles or obstacles in their blind spot that might not be visible in the mirrors. This area is critical, especially if the driver is merging back into a lane or completing a turn, as it ensures safety by confirming that the space is clear.

In addition to the left side mirror, which helps identify immediate surroundings on that side, checking over the shoulder gives a wider field of view and confirms that there are no unforeseen dangers. This practice is vital because that blind spot is often where other vehicles may be present, and failing to check it can result in unsafe maneuvers.

Other options may provide relevant information for a driver, but they do not specifically address the need to check the blind spot to the left side of the vehicle. Looking through the front window primarily helps in assessing the road ahead, while the rearview and right side mirrors provide additional views of traffic and surroundings but may not cover the driver's blind spot on the left effectively.