Final answer:
Assisting a patient to change clothes after an episode of incontinence best supports psychological safety in mental health care by ensuring the patient's dignity and reducing embarrassment (Option B).
Step-by-step explanation:
The nursing action that best supports the maintenance of psychological safety for a patient with mental illness is assisting a patient to change clothes after an episode of incontinence.
This action respects the patient's dignity and provides a compassionate response to an event that can be embarrassing, thus contributing to a sense of safety and self-worth.
Other options, such as highlighting personal flaws or isolation tactics, can exacerbate negative feelings and decrease psychological safety.
Instead, promoting a therapeutic environment where patients feel respected and cared for is essential.
Interventions could also include psychotherapy, medication such as selective serotonin reuptake inhibitors, or other treatments tailored to the individual's needs.
Hence, the correct answer is Option B.