While They Differ in Some Respects, How Are a Living

While they differ in some respects, how are a living will and a power of attorney similar?

A) They both identify someone to act on your behalf if you become incapacitated.
B) They both make it legal for a physician to perform active euthanasia.
C) They both allow others to know one's preferences concerning issues like whether you want to be put on life support.
D) They both cannot be written until a person is about to lose the ability to make his or her own decisions.