You are given a science question (easy-level) and four answer options (associated with "A", "B", "C", "D"). Your task is to find the correct answer based on scientific facts, knowledge, and reasoning. Do not generate anything else apart from one of the following characters: 'A', 'B, 'C', 'D'. There is only one correct answer for each question.

Electron transport in mitochondria results in a chemiosmotic gradient of which particle across the mitochondrial membrane?  
 (A) ADP (B) ATP (C) protons (D) neutrons
C

If you breathe on a mirror, part of the mirror clouds up. What are you actually seeing when you see the mirror cloud up?  
 (A) Water droplets that formed from cooled water vapor in your breath (B) Carbon dioxide that you are breathing out from your lungs (C) Oxygen that you are breathing out from your lungs (D) Cooled nitrogen in the air around you
A

A student observes a glowing band across the night sky. This glowing band is most likely  
 (A) orbiting planets in the solar system. (B) a partial view of the Milky Way galaxy. (C) an asteroid orbiting the Sun. (D) light from stars in a distant galaxy.

B