I believe the answer is B. decomposers moving nitrogen into consumers.
Answer: Permafrost-carbon feedback
Explanation: Permafrost is the later of the earth surface that are frozen, It Thawing is a major cause of Global warming, Permafrost contain many Green House gases such as Methane and other hydrocarbons as the Permafrosts Thaw,unlocking of the carbon deposits on the earth takes placeas all this hydrocarbons released causes flooding,high temperatures and excessive decomposition of organic matters.
