instruction:
You are given a science question (hard-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:
A group of students observed the formation of bubbles when water boiled. What happened to matter because of the physical change to the water?  
 (A) New matter was created in the bubbles. (B) Old matter was destroyed as the water turned to gas. (C) Matter was conserved when it changed form. (D) The composition of the matter changed.
answer:
C


question:
How are green plants an important part of the carbon dioxide-oxygen cycle?  
 (A) They add oxygen to the soil. (B) They release oxygen into the air. (C) They fix carbon dioxide in the soil. (D) They store carbon dioxide in roots.
answer:
B


question:
Which sequence of energy transformations occurs after a battery-operated flashlight is turned on?  
 (A) electrical -> light -> chemical (B) electrical -> chemical -> light (C) chemical -> light -> electrical (D) chemical -> electrical -> light
answer:

D


