What must you ensure about the truck's position before performing a safe start?

Answer: B — The truck must be in neutral

Before initiating a safe start of the truck, it's crucial to confirm that the vehicle is in neutral. This position ensures that the transmission is disengaged from the engine, allowing the truck to start without moving unexpectedly. If the truck were in gear, there could be a risk of it lurching forward or backward when started, which could lead to accidents or injury. Ensuring that the truck is not turned off is important, but it does not relate directly to the readiness for starting. Parking on a slope could pose additional safety risks, especially if the vehicle were not secured properly. Lastly, having the truck in drive would definitely create a hazardous situation, as the vehicle could move immediately upon starting, which is why neutral is the essential position for a safe start.