If Charles Keeling Had Chosen to Carefully Measure Methane (Instead

Multiple Choice

If Charles Keeling had chosen to carefully measure methane (instead of carbon dioxide) each month at the Mauna Kea Observatory,what might he have NOT found?

A) the gradual increase of that gas, year after year.
B) the same seasonal changes of that gas, year after year.
C) the effects of several volcanic eruptions, on atmospheric gas composition.
D) the effects of any massive melting/decomposition of methane hydrates.