Final answer:
The outermost level of an individual's ethical structure consists of actions that most people would not consider unacceptable or unethical.
Step-by-step explanation:
The outermost level of an individual's ethical structure consists of actions that most people would not consider unacceptable or unethical (option D). These actions are generally considered to be within the boundaries of societal norms and values.
They may not cause extreme ethical discomfort (option B) or be serious ethical violations (option A) that are universally condemned. While behavior that calls for stringent measures against the person (option C) may be a part of ethical structures, it is not specifically associated with the outermost level.