Answer: the main anthropogenic greenhouse gas produced in the united states.
Anthropogenic means that the man is the responsible for its generation.
Fuel consumption for vehicles, factories and houses generates huge amounts of CO2.
Let's review the other options:
a. the
most abundant greenhouse gas
FALSE: The most abundant greenhouse gas is water vapor.
b. the most potent (per molecule) gas. of the
greenhouse gases
Methane is considered more potent than CO2 as heat-trapping.
c. the only greenhouse gas presently decreasing in the
atmosphere
CO2 has not decreased but increased.
d. the main anthropogenic greenhouse gas produced in the united
states
TRUE as stated initially
e. the only greenhouse gas presently increasing in the atmosphere
FALSE: Methane (CH4) is also increasing.
