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:
Which statement correctly describes a relationship between two human body systems?  
 (A) The digestive system absorbs nutrients which are transported by the nervous system. (B) The digestive system absorbs nutrients which are transported by the circulatory system. (C) The circulatory system exchanges gases which are transported by the nervous system. (D) The circulatory system exchanges gases which are transported by the digestive system.

Ex Output:
B


Ex Input:
A student conducts an investigation using mold spores. In one part of the investigation, he needs to closely examine a spore sample. Which piece of equipment does the student need to use to keep mold spores from entering his respiratory system?  
 (A) breathing mask (B) safety goggles (C) rubber gloves (D) lead smock

Ex Output:
A


Ex Input:
Which of the following correctly orders part of a fish's respiratory system from the least complex to most complex?  
 (A) cells -> gills -> tissues (B) cells -> tissues -> gills (C) gills -> tissues -> cells (D) tissues -> gills -> cells

Ex Output:

B