[TG. O5HJA specific location in America produces electricity only from fossil fuels and geothermal energy. The table below shows the amount of methane in the atmosphere of the location from 1960 to 2000
Year
1960
1970
1980
1990
2000
Methane concentration (in parts per million by volume)
124
118
269
185
131
Based on the table, which of these conclusions is most likely correct about the period between 1970 and 1980?
O Electricity was generated only from fossil fuels
Electricity was generated only from geothermal energy
O Several fossil fuel units were replaced by geothermal units.
O Several geothermal units were replaced by fossil fuel units.