instruction:
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:
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
answer:
C

question:
Some types of bacteria can only live where oxygen is not present. These bacteria were well adapted to life on Earth over 2 billion years ago. Which of the following changes caused many of these bacteria to become extinct?
(A) the slow movement of tectonic plates (B) the varying temperatures of each season (C) an increase in volcanic activity under the oceans (D) an increase in the number of photosynthetic organisms
answer:
D

question:
Which method would be best for scientists to use to determine the absolute age of a Precambrian igneous rock?
(A) index fossils (B) law of superposition (C) radiometric dating (D) law of original horizontality
answer:
C