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.

[EX Q]: Which process in the water cycle returns water from the surface of Earth to the atmosphere?  
 (A) condensation (B) evaporation (C) precipitation (D) runoff
[EX A]: B

[EX Q]: What property is the same for each atom of an element?  
 (A) energy (B) mass number (C) atomic number (D) number of neutrons
[EX A]: C

[EX Q]: The meanings of mass and weight can often be confused. Which is an example of a change in both mass and weight?  
 (A) visiting the Moon (B) a stone eroding in a river (C) living on the space station (D) a ship floating on the ocean
[EX A]:
B