[Solved] Which of the following is the best explanation for why cells are considered the smallest units of living things. A) Cells are highly ordered and complex. B) Cells are the simplest structure to fit all of the characteristics necessary to be considered alive. C) Cells have the ability to reproduce identical copies of themselves in a process called mitosis. D) Cells cannot be seen with the naked eye and are considered microscopic. Opiates: A group of drugs derived from opium used for their analgesic, sedative, and narcotic effects. Mimic: Imitation of someone or something, often to entertain or to learn. Depressants: Drugs that slow activity in the central nervous system. Central Nervous System: The part of the nervous system consisting of the brain and spinal cord, responsible for processing and sending out information.