The answer would be B. Cats.
Cats are the most advanced organisms between the options thus have the greatest amount of cell specialization.
<span>simple organic molecules can form spontaneously under conditions like those thought to prevail early in Earth's history</span>
Answer: Serotonin
Explanation:
Serotonin is an hormone, derived from the amino acid, tryptothan. It is involved in vasodilation, sleep regulation, mood changes, capillary permeability, and causes contraction of smooth muscles like that of the stomach to signal hunger.
The answer is; catalyst
These proteins are called enzymes. They work by lowering the activation energy of reactants and hence speed up the biochemical reaction. They are not affected in the process hence one enzyme molecule can catalyze many reactions. An example of such an enzyme is carbonic anhydrase that enables carbon dioxide to dissolve in blood plasma as carbonic acid.