The document where you can appoint another person to make health care decision on your behalf is called:
Answer: (b), Durable Power of Attorney for Healthcare
A "durable power of attorney for healthcare" is a document in which a person is appointed to make health care decisions for another should that person be unable to make the decisions for himself or herself. A durable power of attorney may also include instructions regarding the person's wishes and desires for health care should that person be unable to personally make such decisions.