The Various Classes of Coal Have Been Exposed to High

Multiple Choice

The various classes of coal have been exposed to high heat and pressure for different periods of time.Which of the following lists in order the classes of coal from lowest to highest energy content?

A) anthracite,bituminous,sub -bituminous,lignite
B) lignite,sub -bituminous,bituminous,anthracite
C) lignite,bituminous,sub -bituminous,anthracite
D) sub -bituminous,bituminous,lignite,anthracite
E) lignite,anthracite,sub -bituminous,bituminous