Despite the Lack of Federal Government Action, in 2011

Despite the lack of federal government action, in 2011

A) CO₂ emissions in the United States were down due to newer fuel-efficient cars.
B) CO₂ emissions in the United States were down due to newer power plants coming on line that used natural gas instead of coal.
C) CO₂ emissions in the United States were down due to tougher emissions laws passed by states.
D) CO₂ emissions in the United States were down due to a colder winter.
E) CO₂ emissions in the United States were down due to newer fuel-efficient cars, and due to newer power plants coming on line that used natural gas instead of coal.