PLZ HELP ASAP A specific location in America produces electricity from fossil fuels and geothermal energy. The table below shows the amount of nitrogen oxide in the atmosphere of the location from 1960 to 2000.

Year 1960 1970 1980 1990 2000
Nitrogen oxide concentration (in parts per million by volume) 285 258 234 199 117

Based on the table, which of these conclusions is most likely correct?

Geothermal energy was replaced by fossil fuels in 2000.
Fossil fuels were replaced by geothermal energy in 2000.
The least amount of fossil fuel was used between 1980 and 1990.
The greatest amount of fossil fuel was used between 1960 and 1970.