The distance versus time graph for Object A and Object B are shown.

{IMAGE} A graph titles Distance vs Time. A curved line is drawn through point 10 on y axis and this line is labeled Object A. The graph for Object B is a straight slanting line passing through the origin

Which statement best describes the motion of Object A and Object B?

Both objects move with variable speed.
Both objects move with constant speed.
Object A moves with constant speed and Object B moves with variable speed.
Object A moves with variable speed and Object B moves with constant speed.