Please answer the following question: Here's a short story: 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..  What is the most sensical answer between "pile of rocks" and  "pile of pillows"?
A:
pile of pillows