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.
--------
Question: In the human body, which system functions primarily to defend the body against disease?  
 (A) digestive (B) immune (C) nervous (D) respiratory

Answer: B


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

Answer: B


Question: Brittany pedaled her bicycle quickly on a level surface. When she stopped pedaling and coasted, the bicycle slowed and came to a stop. What happened to the energy of the moving bicycle as it coasted to a stop?  
 (A) It was transferred to heat due to friction. (B) It was reabsorbed into Brittany's muscles. (C) It was stored in the bicycle wheels as potential energy. (D) It was transferred to the air in the form of visible light.

Answer:
A