有

11. Logging industry official: Harvesting trees from old-growth forests for use in manufacture can reduce the amount of carbon dioxide in the atmosphere, since when large old trees die in the forest they decompose., releasing their stored carbon dioxide. Harvesting old-growth forests would, moreover, make room for rapidly growing young trees, which absorb more carbon dioxide from the atmosphere than do trees in old-growth forests.

Which one of the following, if true, most seriously weakens the official's argument?

(A) Many old-growth forests are the home of thousands of animal species that would be endangered if the forests were to be destroyed.

(B) Much of the organic matter from old-growth trees, unusable as lumber, is made into products that decompose rapidly.

(C) A young tree contains less than half the amount of carbon dioxide that is stored in an old tree of the same species.

(D) Much of the carbon dioxide present in forests is eventually released when wood and other organic debris found on the forest floor decompose.

(E) It can take many years for the trees of a newly planted forest to reach the size of those found in existing old-growth forests.

为什么选B 啊？请赐教。