An inclined plane is a tilted surface designed to aid in supporting or transporting a load.
Inclined planes serve many purposes, including use as wheelchair ramps, and do not merely apply to the unloading of merchandise. They are quite useful in transportation, as they readily bridge significant gaps in height and can support heavy loads. Inclined planes are not intended for suspension.
B Inclined planes are tilted surfaces designed to assist in suspension.
C Inclined planes are not useful implements and have been replaced by more effective methods of transportation.
D An inclined plane is intended to aid only in unloading merchandise.