im going to guess its a cause think of it this way its like family in a way if raccoons and red pandas are a more common ancestor than they might have been family along the lines of history somewhere if its not a than d i hop this helps and id pick d it sounds more frequent
It is essential for all living things. Fixation: In order for organisms to use atmospheric nitrogen (N2), it must be “fixed” or converted into ammonia (NH3).
