Final answer:
Dr. Steinmetz's decision to withhold treatment for the terminal cancer is an example of autonomy, allowing the patient to die.
Step-by-step explanation:
The correct answer is C) Autonomy.
Dr. Steinmetz's decision to follow the wishes of her patient and withhold treatment for the terminal cancer aligns with the principle of autonomy. Autonomy is the principle that states patients have the right to make decisions about their own healthcare. In this case, the patient's wish to die is respected and treatment is withheld.