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 Q]: Which animal eats only plants?  
 (A) Cat (B) Dog (C) Lion (D) Rabbit
[EX A]: D

[EX Q]: 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 A]: A

[EX Q]: Some events on Earth happen instantly while others take thousands of years to occur. Which process takes the longest time to complete?  
 (A) rivers rising due to storms and floods (B) evaporation of water from the leaves of a plant (C) weathering of a rock to form small rocks and sand (D) movement of small pieces of rock by flowing water
[EX A]:
C