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.

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
B

Which of these is a renewable resource found in Nevada?  
 (A) zinc metal (B) gravel deposits (C) petroleum products (D) geothermal energy
D

A student needs to find the mass of an atom. The numbers of which atomic particles determines the mass of the atom?  
 (A) only its protons (B) only its electrons (C) both its protons and neutrons (D) both its neutrons and electrons

C