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 Input:
In a lab investigation, a student notes that two metal blocks have the same mass. Based on this observation, if the two blocks were put on opposite sides of a balance, they would best represent  
 (A) balanced forces. (B) unbalanced forces. (C) equal and opposite reactions. (D) objects in motion.

Ex Output:
A


Ex Input:
Which series correctly represents the levels of organization in an organism?  
 (A) cells -> organs -> organ system -> tissue (B) cells -> tissue -> organs -> organ system (C) tissue -> cells -> organ system -> organs (D) tissue -> organ system -> cells -> organs

Ex Output:
B


Ex Input:
If the Earth did not tilt on its axis in relation to the sun, which of the following would also be true?  
 (A) There would be no seasons. (B) One Earth-year would be 14% longer. (C) The Earth would spin at a different rate. (D) Temperatures at the Earth's equator would cool.

Ex Output:

A