The comammox bacteria play a role in nitrification and therefore in the nitrogen cycle. Other microbes, with distinct ecological niches, also participate in the nitrogen cycle. The metabolic reactions involving nitrogen that bacteria perform include: nitrogen fixation (N2 → NH3), nitrification (NH3 → NO3 - or NO2 -), and denitrification (NO3 - or NO2 - → NO, N2O, and N2), all of which make up the nitrogen cycle. Each of these reactions is carried out by a unique set of microorganisms with a distinct ecological niche. Drag the appropriate items to their respective bins.

A. microbes that oxidize inorganic nitrogen compounds

B. obligate anaerobes

C. chemoorganotrophs

D. chemolithotrophs

E. obligate aerobes

F. facultative aerobes

Bin 1. Nitrogen fixation

Bin 2. Nitrification

Bin 3. Denitrification