Final answer:
The 'organism' represents a higher level of organizational complexity than organs, being the encompassing level that includes all other levels such as cells, tissues, and organ systems within a living being.
Step-by-step explanation:
When considering the levels of organization of the human body, the answer to which choice represents a higher level of organizational complexity than organs is d) Organism.
Life processes of the human body are maintained at several levels of structural organization, including the chemical, cellular, tissue, organ, organ system, and organism levels. Each level represents an increase in complexity with the organism level being the highest. At this level, an organism is a living being that has a cellular structure and can independently perform all physiological functions necessary for life. In humans, all cells, tissues, organs, and organ systems work together to maintain the life and health of the organism.