Please choose the correct answer to the question: Two balls rolled down two identical inclined planes. The balls were exactly the same mass and size, but one ball rolled down the inclined plane faster. Identify a possible reason that one ball rolled faster than the other ball.

Answer1: One ball was red and the other ball was blue. Answer2: One ball was new and the other ball was old. Answer3: One ball was shiny and the other ball was dull. Answer4: One ball was sticky and the other ball was smooth.

Answer format: answer1/answer2/answer3/answer4