NASW Code of Ethics.
Take this KSA: Client Self-Determination. It's in the code a couple of times. First in the Ethical Principles, up top:
Value: Dignity and Worth of the Person
Ethical Principle: Social workers respect the inherent dignity and worth of the person.
Social workers treat each person in a caring and respectful fashion, mindful of individual differences and cultural and ethnic diversity. Social workers promote clients’ socially responsible self-determination. Social workers seek to enhance clients’ capacity and opportunity to change and to address their own needs. Social workers are cognizant of their dual responsibility to clients and to the broader society. They seek to resolve conflicts between clients’ interests and the broader society’s interests in a socially responsible manner consistent with the values, ethical principles, and ethical standards of the profession.
Want it more spelled out? The code is ready to do just that, in 1.02, Self-Determination:
Social workers respect and promote the right of clients to self-determination and assist clients in their efforts to identify and clarify their goals. Social workers may limit clients’ right to self-determination when, in the social workers’ professional judgment, clients’ actions or potential actions pose a serious, foreseeable, and imminent risk to themselves or others.
Social workers don't have to agree with everything their clients believe and do. Gently exploring pros and cons is one thing, but imposing values and judgments on clients is another.
How might this show up on the social work licensing exam? Take a look at this free practice question from SWTP to get an idea. If a client isn't planning to do harm to self or others--imminent harm--social workers are to back off. Clients get to choose how to live their lives. Sometimes it's hard to watch, but that's all part of being an ethical social worker.
For more about client self-determination, take a look at these Eye on Ethics columns from Social Work Today: Making Difficult Decisions and The Challenge of Paternalism in Social Work. But really all you have to do is read the above section of the Code of Ethics, and you're up to speed!
Good luck on the exam!