<span>In biological terms, the structure of a species is usually best adapted to give it the most advantageous functional ability, though this is not always the case. When a structure has a function that allows the species to survive and promulgate its genetic structure, the individual will be more likely to reproduce its genotype over those that are not structurally advantageous.</span>
B.) is the answer. I think it is. I'm not completely sure. But I think this is the right answer. Can you mark me brainliest if it is please.
The substance is your saliva