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 scientist is credited with using a telescope in the seventeenth century to discover the moons of Jupiter?  
 (A) Galileo (B) Kepler (C) Einstein (D) Newton

Ex Output:
A


Ex Input:
Similar types of cells form tissues. What is the next level of complexity formed from the grouping of tissues?  
 (A) organs (B) organelles (C) organisms (D) organ systems

Ex Output:
A


Ex Input:
Which of the following was probably most important in the formation of dark, fertile soil that is good for farming?  
 (A) plant decomposition (B) radioactive decay (C) water erosion (D) wind erosion

Ex Output:

A