Which of the following statements is true regarding social workers and clients' relatives?

The statement that social workers should avoid sexual activities with clients' relatives due to potential risk of exploitation is aligned with the ethical guidelines set forth in the NASW Code of Ethics. It is vital for social workers to maintain professional boundaries to ensure the integrity of the therapeutic relationship and to prevent any exploitation or harm that may arise from dual relationships.

Engaging in sexual relationships with clients or their relatives can create conflicts of interest and might compromise the professional judgment of the social worker. The power dynamics inherent in these relationships can lead to situations where clients' relatives may feel pressured or unable to freely consent. By adhering to the guideline of avoiding sexual activities in this context, social workers prioritize the welfare of their clients and uphold the ethical standards of the profession.

The other statements imply scenarios that could contravene ethical practices. Allowing sexual contact with both parties’ consent overlooks the potential for exploitation inherent in such cases. Informing a client before engaging with relatives does not address the ethical implications of crossing professional boundaries, and engaging in casual relationships after termination of services remains problematic, as it can still affect the professional's objectivity and the client's well-being.