A

Reasoning: The Mental Healthcare Act 2017 allows any competent adult with mental illness to write an advance directive that both (a) specifies future treatment choices and (b) appoints a “nominated representative” (caretaker) to act on their behalf; this mechanism is termed an Advance Directive [Philip et al., 2019, PMID 31040457; Duffy & Kelly, 2018, PMID 30122262].