instruction:
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.
question:
What has occurred when bubbles form in a liquid that is being heated?  
 (A) Oxygen is absorbed from the air. (B) Heat is radiating in the liquid. (C) The boiling point has been reached. (D) Molecular stability in the liquid is increasing.
answer:
C


question:
What season is the Northern Hemisphere experiencing when it is tilted away from the Sun?  
 (A) spring (B) summer (C) autumn (D) winter
answer:
D


question:
A boy and his sister both play piano. Playing piano is an example of  
 (A) a physical change (B) an inherited trait (C) a life function (D) a learned behavior
answer:

D