Final answer:
The competent patient is the appropriate decision maker in refusing life-sustaining interventions, as her right to autonomy must be respected according to bioethics principles and the concept of 'dying with dignity'.
Step-by-step explanation:
In the scenario where a competent 70-year-old female patient refuses further life-sustaining interventions, including artificial nutrition and hydration, the appropriate decision maker is the patient herself (a). Since she is competent and fully aware of the consequences of her decision, her autonomy should be respected. The daughter (b) and the doctor (c) may have their opinions, but ultimately it is the patient's right to make decisions about her own body and medical care. Though the doctor and the daughter disagree with the patient's choice, and an ethics consult team has been initiated to assess the situation, they serve to provide guidance rather than to make the decision for the patient.
The principles of bioethics emphasize respect for autonomy, beneficence, non-maleficence, and justice. In this case, respect for autonomy is paramount, and the law typically upholds a competent individual's right to refuse treatment. This is in line with the concept of 'dying with dignity', a principle upheld in various medical ethics discourses and legislations on end-of-life care. Discussions around end-of-life decisions have been highlighted in notable cases like those of Terri Schiavo and others, where the withdrawal of life support and the right to refuse treatment were central issues.