Although the concept of free will is essential to that of moral responsibility, its role in determining responsibility is not the same in all situations. We hold criminals morally responsible for the damage they cause, assuming that they freely chose their activities. But we do not hold someone who has a heart attack while driving morally responsible for the damage caused, if any, even when we have good reason to believe that the heart attack could have been prevented by eating different foods and that one' s choice of diet is made freely. The claim that a choice of diet can affect whether or not one has a heart attack plays which one of the following roles in the argument? ['It is a subsidiary conclusion of the argument.', 'It is used to show that we should hold someone morally responsible for damages caused by having a heart attack while driving.', 'It is cited as evidence that our concept of moral responsibility should be the same in all situations.', 'It is used in support of the conclusion of the argument.']