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:
A class made a solar cooker out of a large can. What color should they paint the can in order to collect the most heat?  
 (A) black (B) green (C) pink (D) white

Ex Output:
A


Ex Input:
Many things can contribute to the development of a theory. A student made a list of some things that might help scientists develop a theory. Observations Calculations Conversations Publications From the student's list, which must be used in the development of every theory?  
 (A) Observations (B) Conversations (C) Publications and calculations (D) Calculations and conversations

Ex Output:
A


Ex Input:
When plants undergo photosynthesis, a reaction produces sugar, oxygen, and water. During respiration, stored energy from the products of photosynthesis is converted to usable energy. In what form is the energy stored prior to use in respiration?  
 (A) chemical energy (B) kinetic energy (C) light energy (D) heat energy

Ex Output:

A