Before preparing to conduct your pre-trip inspection, what should the driver do before climbing under the vehicle?

Before climbing under the vehicle to conduct a pre-trip inspection, blocking the wheels is a crucial safety measure that ensures the vehicle remains stationary. This prevents any unintended movement, which could result in serious injury to the driver during the inspection process. Properly blocking the wheels secures the vehicle in place, especially if it is on an incline or if the suspension is under stress.

Engaging the parking brake is an important step as well, but merely engaging the brake may not be sufficient if the vehicle is on an incline or if there's a risk of it rolling. Therefore, blocking the wheels provides an additional layer of safety.

Other options, such as checking the engine oil, inspecting the mirrors, or engaging the parking brake, are important parts of the overall vehicle inspection process, but they do not specifically address the immediate safety requirement of ensuring the vehicle does not move while the driver is under it.