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:
Which characteristic best identifies a pure substance?  
 (A) shape (B) texture (C) melting point (D) state of matter

Ex Output:
C


Ex Input:
A student wants to organize a group of animals into two categories based on observable external features. Which display will most appropriately show the two categories of animals?     
 (A) a timeline (B) a pie chart (C) a data table (D) a line graph

Ex Output:
C


Ex Input:
How does the appearance of a constellation change during the night?  
 (A) Its shape appears to become longer. (B) Its position appears to shift relative to the horizon. (C) Its brightest stars begin to appear orange. (D) Its distance to the North Star decreases.

Ex Output:

B