Question

prevent the vehicle from rolling. this can be achieved by applying the parking brake or by placing chocks behind the wheels that are not being lifted.
always work on firm, level flooring (preferably concrete). this prevents the jack from sinking in the ground and the car from dropping off the jack. this also prevents the presence of dirt and debris, that could keep the wheels from rolling freely.
the jack support cup should be positioned under a solid point on the car body or chassis.
often the car manufacturer specifies designated lifting points. these lifting points are shown in the corresponding service information and/or vehicle owners manual. positioning the jack at a non - designated lift point is dangerous and could cause damage to the vehicle.
note: some vehicles are designed with lift points that require a special adapter to be used in conjunction with the floor jack.
what are the best positions for the jack support cup?
any position along the pinch rail.
designated lifting points, specified by the car manufacturer.
any position on the vehicle.

Explanation:

The text clearly states that the jack support cup should be positioned under a solid point on the car body or chassis, and often the car manufacturer specifies designated lifting points. Positioning the jack at a non - designated lift point is dangerous and could cause damage to the vehicle.

Answer:

B. Designated lifting points, specified by the car manufacturer.