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.

Example Input: A student makes the hypothesis that rubbing a balloon on a shirt and then putting it on the wall will cause it to stick due to static electricity. Once the experiment is conducted, what is the best way to prove that the results are reliable?  
 (A) Write down the results of the experiment. (B) Repeat the same experiment several times. (C) Make another hypothesis about static electricity. (D) Conduct a different static electricity experiment.
Example Output: B

Example Input: A combination of processes occurs when stars are forming. Which is one process most likely associated with the formation of new stars?   
 (A) Hydrogen in the cores of the stars is exhausted. (B) Material accumulates from stars that have died. (C) Elements in the stars such as iron undergo fusion. (D) Cores of stars become twice as massive as the Sun.
Example Output: B

Example Input: Which of these meals would give you most of the nutrients that you need?  
 (A) Meat, milk, and a piece of chocolate (B) Bread, vegetables, and fish (C) Vegetables, fruits, and water (D) Meat, fish, and bread
Example Output:
B