imagine a person is diagnosed a terminal illness.

which one of the answers represents your stance on this matter the best?
should discontinuation of life support be made universally illegal (1)
or should a patient be allowed to refuse treatment
- in case he's (or she's) mentally competent to make the decision (2) or
- if he provided advance directive through a living will or appointed a health care proxy with power of attorney? (3).

should a legal guardian be able to refuse treatment if no advance health care directive has been given by a now unconscious, terminally ill patient? (4 - not like the schiavo case)

should a legal guardian decide the course of treatment if no advance health care directive has been given by a comatose patient whose prognosis predicts minimum to no chances of recovery? (5 - see schiavo case)

all possibilites but the first imply non-active euthanasia by cutting life-sustaining measures the patient is dependent on for further survival.
what about the matter of quality of life and dignified death without suffering?
should active, voluntary euthanasia using lethal substances a.k.a. assisted suicide also be allowed for old people that suffer from excruciating pain even though their disease or condition does not directly lead to death but is incurable? (6)