From the options given, the best option to answer the question is (C) involuntary euthanasia.
Involuntary euthanasia differs from voluntary and non-voluntary euthanasia, in that voluntary euthanasia is requested by the individual who is suffering from a terminal disease or refuses to have severe medical treatments for the rest of his or her life, while non-voluntary euthanasia is done to someone who cannot make their wishes known (whether or not she or he would rather live or die) such as someone in a coma.