TASK DEFINITION: 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.
PROBLEM: Which example best illustrates an action-at-a-distance force?
(A) lifting a box (B) an apple falling (C) pulling a nail out of wood (D) a car moving along a flat surface

SOLUTION: B

PROBLEM: Many scientists think that burning fossil fuels has increased the amount of carbon dioxide in the atmosphere. What effect would the increase of carbon dioxide most likely have on the planet?
(A) a cooler climate (B) a warmer climate (C) lower relative humidity (D) more ozone in the atmosphere

SOLUTION: B

PROBLEM: Technological advancements in the logging industry have had both negative and positive effects on forest ecosystems. The most likely negative effect of more efficient logging techniques is
(A) an increase in the time needed for transporting wood. (B) safer work environments for loggers. (C) a change in the chemical and physical makeup of land and water. (D) a decrease in the cost of wood and paper products.

SOLUTION:
C