Parasympathetic nerves govern involuntary actions such as pupil dilation, peristalsis, gland secretions, etc.
In this question in which is the major source then of free oxygen in the earth's Proterozoic atmosphere is being produce by the evaporation of the ocean water. Hope this answer would be of big help to this assignment then.
Answer: The Organism is most likely to be a starfish
Oh.... very nice! Yes seeing is nice