Which of These Potential Results of Applying a Metabolic Poison

Which of these potential results of applying a metabolic poison to the rhizoids of Polytrichum should interfere the least with the ability to draw valid conclusions from this experiment?

A) If, upon dying, the rhizoids leak nitrogenous compounds into the soil before final nitrogen content is measured.
B) If, upon dying, decomposition of the rhizoids introduces nitrogenous compounds to the soil before final nitrogen content is measured.
C) If the metabolic poison is hydrogen cyanide (HCN) or sodium azide (NaN₃) , and much of the poison remains in the soil.
D) If the metabolic poison acts against the mitochondria of the rhizoid cells.
E) If the metabolic poison absorbs nitrogen and strongly adheres to soil particles, acting as a sort of glue.