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 car runs out of fuel while traveling on a level road and eventually comes to a stop. Which of the following best explains why the car stops?  
 (A) Some of the energy of the car was lost to friction. (B) Some of the energy of the car was destroyed. (C) The amount of kinetic energy increased. (D) The amount of useful energy increased.

Ex Output:
A


Ex Input:
Claudia's teacher places a photograph of an organism on the board. He asks Claudia to determine if the organism is a plant or an animal. The answer to which question will best help Claudia determine if the organism is a plant or an animal?  
 (A) Does the organism have cells? (B) Does the organism reproduce? (C) Does the organism live in the forest? (D) Does the organism make its own food?

Ex Output:
D


Ex Input:
The average temperature of Earth's surface has increased approximately 1°C in the past century. Which of the following can best explain this increase in temperature?  
 (A) higher levels of oxygen in the atmosphere (B) lower levels of ozone in the atmosphere (C) higher levels of carbon dioxide in the atmosphere (D) lower levels of nitrogen in the atmosphere

Ex Output:

C