In general, why does a toy car change direction when crossing a boundary between two surfaces, such as hard plastic and a carpet, on which its speed is different? choose the best explanation based on what you’ve learned in this extension. select one: a. the wheels of the car move at a different speeds on each surface, so the direction they move in is different. b. between the time the first wheel crosses the boundary and the last wheel of the car does so, the car wheels are moving at different speeds. this causes the car to turn either left or right. c. between the time the first wheel of each axle of the car crosses the boundary and last wheel of each axle does so, the wheels on the same axle on moving at different speeds. this causes the car to turn left or right. d. the car turns slightly crossing the boundary because the amount of friction the car experiences on each surface is different, so the interaction between the car and the surface changes, which pushes the car slightly to the left or right.