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.

The moon goes through phases as it revolves around Earth. During which phase of the moon would it be possible for a solar eclipse to occur?  
 (A) new moon (B) full moon (C) waning (D) waxing
A

Which step will most likely ensure that the results of an investigation are valid?  
 (A) using a computer to graph results (B) verifying that results match the original hypothesis (C) comparing the results with those of other scientists (D) eliminating any results that appear to be abnormal
C

The human body has different levels of organization. In the structural organization of the central nervous system, which is an organ?  
 (A) brain (B) grey matter (C) nerve (D) neuron

A