What should a driver do if a warning light turns on while driving?

Answer: B — Assess the issue when it's safe to do so

When a warning light turns on while driving, assessing the issue when it's safe to do so is the most prudent action. This approach allows the driver to maintain control of the vehicle and ensures safety before investigating the problem. Ignoring the warning could lead to serious mechanical issues or unsafe driving conditions, potentially resulting in accidents or further damage to the vehicle. Stopping immediately might not be safe in all situations, such as on a busy highway, where pulling over could create a hazard for both the driver and other road users. Calling for roadside assistance without first assessing the situation does not provide an opportunity to diagnose any issues that may still allow the driver to continue safely or to determine if immediate assistance is necessary. Therefore, a thoughtful evaluation once it's safe to do so can help in making an informed decision about the next steps.