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.

Input: Consider Input: During a biochemical reaction, pyruvate (C3H4O3) is converted into carbon dioxide (CO2) and water (H2O). In what cellular organelle does this biochemical reaction occur?  
 (A) nucleus (B) cytoplasm (C) mitochondria (D) endoplasmic reticulum

Output: C


Input: Consider Input: Which of these is a renewable resource found in Nevada?  
 (A) zinc metal (B) gravel deposits (C) petroleum products (D) geothermal energy

Output: D


Input: Consider Input: A student divides several cubes into two groups, based on whether or not each cube can float in later. What property is the student using to classify the cubes?      
 (A) weight (B) density (C) conductivity (D) mass


Output: B