Final answer:
A Living Will is the specific legal document that directs relatives and care providers about the extent of treatment that may be given to patients who cannot speak for themselves. It may include a health care proxy.
Step-by-step explanation:
The specific legal documents that direct relatives and care providers about the extent of treatment that may be given for patients who cannot speak for themselves is known as a Living Will. A living will is a written legal document that details specific interventions a person wants and may include a health care proxy, which appoints a specific person to make medical decisions if the patient is unable to speak for themselves. Other options mentioned, such as a Power of Attorney and Do-Not-Resuscitate Order (DNR), are separate legal documents that serve different purposes.