In this task, you are given a multiple-choice question and you have to pick the correct option. Answer with option indexes (i.e., "A", "B", "C", and "D").

Humans contribute to environmental pollution (A) by purchasing products made from recycled products (B) by switching to energy efficient appliances (C) by leaving behind refuse on public beaches (D) by frequently recycling paper and plastic
C

Jeff noticed that the big dipper was in a different spot in the sky at 2am than where it was at 10pm. Why? (A) because of the earth's orbit (B) the stars had rotated (C) Jeff had been instantly transported thousands of miles from where he'd been at 10pm. (D) the earth had turned
D

When wheels are squealing on a blacktop, friction (A) works against motion (B) stops motion (C) removes forward motion (D) makes things rough

A