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.

Input: Consider Input: Which of these is a property of water that allows it to transport materials through the Earth system?  
 (A) It expands as it solidifies. (B) It is transparent. (C) It dissolves many substances. (D) It is a compound.

Output: C


Input: Consider Input: The Sun is classified as a star. Which characteristic identifies the Sun as a star?  
 (A) The Sun spins on its axis. (B) The Sun is located outside the Milky Way galaxy. (C) The Sun is part of the Big Dipper. (D) The Sun produces light and energy in a nuclear reaction.

Output: D


Input: Consider Input: Which mixture contains ingredients that can be easily separated?  
 (A) bread (B) fruit salad (C) ocean water (D) soda water


Output: B