Graph A represents constant speed so the answer for this is the car is moving at constant speed. Time is increasing to the right, whereas distance is increasing constantly with time.
Graph B represents the car is coming back because from the starting point it is decreasing because while velocity is +, the magnitude keeps on lowering.
Graph C represents the car is stopped since it time increasing to the right but there is no change in speed.
Graph D represents the speed of the car is decreasing because distance in each time interval is decreasing.