The best answer is D, birds.
For more information and details on the way a bird's respiratory system works:
https://asknature.org/strategy/air-flow-patterns-facilitate-efficient-gas-exchange/
Vitamin niacin ( vitamin B3)
I choose the option C.
N2 + 3H2 = 2NH3
The final stage of the mitotic phase is cytokinesis, during which the cytoplasmic components of the daughter cells are separated either by an actin ring (animal cells) or by cell plate formation (plant cells).
Carbon debt, caused by CO2<span> i know that is one of them </span>