Task: Question Understanding
Input (English): Question: Based on analysis of deep ice cores from the Arctic, scientists theorize that early humans caused air pollution. These scientists can make sure their data is correct by (A) analyzing only melted ice cores. (B) analyzing more than one ice core. (C) comparing their data to the expected results. (D) comparing their data to modern pollution levels.?
Output (English): theorize, humans, caused, air, pollution., data, correct