Please answer the following question: Choose between "pile of rocks" and  "pile of pillows". Question: Carla is driving a test car over different surfaces. She drives the car over a pile of pillows and the car drives over them easily. Carla drives the car over a pile of rocks, and the car goes a little slower. The car went easier over the pile of pillows because there was (A) more friction (B) less friction.
A:
pile of pillows