Answer:
D
Explanation:
duplication of the chromosomes
The answer is Denitrification.
Denitrification is the reduction of nitrates back into the largely inert nitrogen gas (N2), completing the nitrogen cycle. This process is performed by bacterial species such as Pseudomonas and Clostridium in anaerobic conditions.
How many can you check? I personally think its all 4 but i could be wrong :)