Burning Coal Causes a More Severe CO₂ Problem Than Burning

Burning coal causes a more severe CO₂ problem than burning other fossil fuels because

A) coal is composed of C, H and O and other fossil fuels do not contain C, H, or O.
B) coal is burned in a mass burn incinerator, which is open air, whereas other fossil fuels are burned in closed systems.
C) the technology does not exists that would filter CO₂ from the emissions, but it has been developed for other fossil fuels.
D) it takes a greater volume of coal to produce one unit of heat energy than other fossil fuels.
E) coal releases more CO₂ per unit of heat energy produced than other fossil fuels