instruction:
You are given a science question (hard-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:
In a lab investigation, students use Brand X batteries in a flashlight and Brand Y batteries in a radio. After two hours, the flashlight stops working, but the radio continues to work. As a result, the students conclude that Brand Y batteries last longer. Which statement about the conclusion of the investigation is most accurate?
(A) The conclusion is valid because they tested two different brands. (B) The conclusion is invalid because the test had multiple variables. (C) The conclusion is valid because they conducted the investigation in a lab. (D) The conclusion is invalid because the real names of the batteries were hidden.
answer:
B

question:
The Moon lacks weather and climate changes like those on Earth. What causes the lack of weather on the Moon?
(A) the lack of water (B) the presence of igneous rock (C) the very thin atmosphere (D) the lack of magnetic poles
answer:
C

question:
Fossilized plants give scientists information about the types of plants that lived long ago. What other information can fossilized plants provide?
(A) what kind of environment existed long ago (B) what kinds of animals were alive long ago (C) what color the plants were long ago (D) what dinosaurs looked like long ago
answer:
A