Final answer:
Simple units, such as cells, work together to create the human brain.
Step-by-step explanation:
Simple units work together to create the . The human body is made up of trillions of cells, which are the basic units of life. These cells work together in a coordinated manner to form tissues, organs, and systems that function together to create the human body. For example, neurons in the brain work together to process information and control the body's functions. Therefore, the correct answer is D. the human brain.
Learn more about The human brain and its composition