Carbon dioxide is a byproduct of respiration while oxygen is a byproduct of photosynthesis.
Remember that a byproduct is a secondary product that is made in the synthesis of another. It is unintended and excreted.
For you to understand the process we can say that the weak will die. If the animal or organism can't get food or find any it is naturally "selected" to die.So a Cuticle could have evolved like that. Hope tgis is useful
The answer would be D, evolved from a common ancestor
Hope this helps!
In the event that the new hypothesis gives a superior expectation about the places of the planets and sun in the universe, then the old hypothesis must be altered or disposed of for the new hypothesis. That is the thing that keeps science "genuine". We change the models we utilize when better data goes along.