Final answer:
The best reply is to affirm that the law requires that treatment must be provided in public hospitals, and hospitalization without treatment would violate a patient's rights.
Step-by-step explanation:
The most helpful response to the concerns of a patient's family considering transferring the patient to a public mental hospital would be option (a): "Under the law, treatment must be provided. Hospitalization without treatment violates patients' rights." This assures the family that legal protections exist to ensure patients receive actual treatment, not just shelter. Public hospitals are obligated to provide a standard of care, which includes appropriate medical treatment, despite the financial concerns the family may have. While public hospitals might not always offer as many choices as private institutions, nor is the right to treatment prioritized based on a patient's psychological stability, the law does require that they provide essential treatment for those admitted.