Question ID:PT2 S2 Q4 Passage:Dried grass clippings mixed into garden soil gradually decompose, providing nutrients for beneficial soil bacteria. This results in better-than-average plant growth. Yet mixing fresh grass clippings into garden soil usually causes poorer-than-average plant growth. Stem:Which one of the following, if true, most helps to explain the difference in plant growth described above? Correct Answer Choice:DChoice A:The number of beneficial soil bacteria increases whenever any kind of plant material is mixed into garden soil. Choice B:Nutrients released by dried grass clippings are immediately available to beneficial soil bacteria. Choice C:Some dried grass clippings retain nutrients originally derived from commercial lawn fertilizers, and thus provide additional enrichment to the soil. Choice D:Fresh grass clippings mixed into soil decompose rapidly, generating high levels of heat that kill beneficial soil bacteria. Choice E:When a mix of fresh and dried grass clippings is mixed into garden soil, plant growth often decreases.