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.

Ex Input:
After a heavy rain, a mudslide flows into a pond and mud mixes into the water. Which of the following is most likely to happen?  
 (A) Fish will have more food. (B) Trees will be able to get more light. (C) Raccoons will not be able to find food. (D) Underwater plants will receive less light.

Ex Output:
D


Ex Input:
Two forms of boron are naturally occurring, boron-10 and boron-11. What difference exists between a boron atom with a 10 atomic mass units (amu) and a boron atom with 11 atomic mass units (amu)?  
 (A) amount of neutrons (B) number of electrons (C) size of protons and neutrons (D) size of electrons and electron cloud

Ex Output:
A


Ex Input:
Which would most likely need to happen for a new plant to grow?  
 (A) Leaves grow out of a stem. (B) Insects get attracted to the petals. (C) A blossom falls into the soil. (D) A seed sprouts into a seedling.

Ex Output:

D