Critical Reasoning

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.
Which one of the following, if true, most helps to explain the difference in plant growth described above?
(A) The number of beneficial soil bacteria increases whenever any kind of plant material is mixed into garden soil.
(B) Nutrients released by dried grass clippings are immediately available to beneficial soil bacteria.
(C) Some dried grass clippings retain nutrients originally derived from commercial lawn fertilizers, and thus provide additional enrichment to the soil.
(D) Fresh grass clippings mixed into soil decompose rapidly, generating high levels of heat that kill beneficial soil bacteria.
(E) When a mix of fresh and dried grass clippings is mixed into garden soil, plant growth often decreases.

IMO:D

A) This doesn't explain the difference in plant growth.
B) It explains why dried clippings cause better than avg growth but doesn't explain why fresh clippings cause poorer-than-avg growth
C) same reason as B
D)Correct - It explains why fresh clippings cause poorer-than average growth and in argument its already mentioned why dried clippings cause better growth.
E) Argument is not concerned about mix of fresh and dried clippings.
IMO D

Yeap OA is D