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]: A condition in bees called "colony collapse disorder" occurs when worker bees leave the hive to collect nectar and never return. How would a decline in the bee population most likely affect a farm ecosystem?  
 (A) There would be a decrease in soil thickness. (B) There would be a decline in fruit production. (C) There would be an increase in plant diseases. (D) There would be an increase in insect pest populations.
[EX A]: B

[EX Q]: Which of the following best represents one particular stage in a life cycle?  
 (A) a fish swimming (B) a seed sprouting (C) a leaf growing (D) a dog eating
[EX A]: B

[EX Q]: How does the energy in each trophic level of an energy pyramid compare to the energy in the preceding level?  
 (A) It has about 5% of the energy from the level below it. (B) It has about 10% of the energy from the level below it. (C) It has about 15% of the energy from the level below it. (D) It has about 20% of the energy from the level below it.
[EX A]:
B