Humans are animals as they are multicellular eukaryotic organisms that are mobile, heterotrophic and can reproduce sexually.
On further classification they belong to the phylum chordates as they possess the five anatomical features present in this phylum at some point in their lives. These features are presence of notochord, endostyle, pharyngeal slits, tail and dorsal nerve chord. They also have bilateral symmetry and possess a coelom.
Humans can be further classified as vertebrates as they possess the vertebral column. It is also known as backbone or spine and is characterized by segmented bone series separated by intervertebral discs. Hence, humans are animals, chordates and vertebrates.
C. It requires active transport because the use of energy is necessary, the natural and opposite flow to this, would be from high to low concentration that requires little to no energy (i.e passive diffusion).
