analyzing only melted ice cores. analyzing more than one ice core. comparing their data to the expected results. comparing their data to modern pollution levels.
I am hesitating between 4 options to answer the following question, which option should I choose?
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
Possibilities:
- analyzing only melted ice cores.
- analyzing more than one ice core.
- comparing their data to the expected results.
- comparing their data to modern pollution levels.

analyzing more than one ice core.