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:
When microorganisms deplete the oxygen in soil through respiration, the soil becomes  
 (A) humus. (B) anaerobic. (C) compost. (D) aerobic.

Ex Output:
B


Ex Input:
In some locations, squirrels sleep for long periods of time during the winter months. Which of the following most likely causes these squirrels to sleep for long periods of time?  
 (A) increase in humidity (B) decrease in temperature (C) clouds forming in the sky (D) winds blowing in the night

Ex Output:
B


Ex Input:
Plate movement can form different features on Earth. The movement of tectonic plates can be both a constructive and a destructive force. At which type of plate boundary is new crust formed?  
 (A) convergent (B) subduction (C) transform (D) divergent

Ex Output:

D