Editorial: It has been suggested that private, for-profit companies should be hired to supply clean drinking water to areas of the world where it is unavailable now. But water should not be supplied by private companies. After all, clean water is essential for human health, and the purpose of a private company is to produce profit, not to promote health. Which one of the following principles, if valid, would most help to justify the reasoning in the editorial? ['The mere fact that something actually promotes human health is not sufficient to show that its purpose is to promote health.', 'Drinking water should never be supplied by an organization that is not able to consistently supply clean, safe water.', 'If something is necessary for human health, then it should be provided by an organization whose primary purpose is the promotion of health.', 'A private company should not be allowed to supply a commodity that is essential to human health unless that commodity is also supplied by a government agency.']