It’s D, Insects the greatest and vertebrae the least
Humans are human because of things such as language, foresight, mind-reading, intelligence, culture, or morality. What we feel and how we effect other people and how other people effect us plays a huge part in what makes us human. Our emotions are what make us human what we feel when something happens whether good or bad is what makes us unique and unlike any other species.
Are there any options given? From this, I would say the answer is diction.
