If current trends continue, by the year 2010 carbon emissions in the United States will soar to a level more than one-third higher than were those in 1990, according to official projections.
(A) will soar to a level more than one-third higher than were those
(B) will soar to a level more than one-third higher than that
(C) would soar to a level more than one-third higher than it was
(D) would soar to a level more than one-third higher than those
(E) would soar to a level more than one-third higher than they were