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.

[Q]: For a technology project, Kyle came up with an idea to build a model bridge. He wants his bridge to span 50 cm and to support a 1 kg object. According to the engineering design process, which of the following should be Kyle's next step?  
 (A) construct prototypes of different kinds of bridges (B) research the different designs of bridges (C) gather the materials needed to build the bridge (D) make a drawing to show how to build the bridge
[A]: B


[Q]: Rocks that contain fragments of bones, shells, and plant remains are most likely  
 (A) crystals. (B) igneous. (C) sedimentary. (D) metamorphic.
[A]: C


[Q]: Which organ system is responsible for the exchange of oxygen and carbon dioxide between the body and the environment?  
 (A) circulatory (B) excretory (C) immune (D) respiratory
[A]:
D