In order to expand its mailing lists for e-mail advertising, the Outdoor Sports Company has been offering its customers financial incentives if they provide the e-mail addresses of their friends. However, offering such incentives is an unethical business practice, because it encourages people to exploit their personal relationships for profit, which risks damaging the integrity of those relationships. Which one of the following principles, if valid, most helps to justify the reasoning in the argument? ['It is unethical for people to exploit their personal relationships for profit if in doing so they risk damaging the integrity of those relationships.', "It is an unethical business practice for a company to deliberately damage the integrity of its customers' personal relationships in any way.", 'If it would be unethical to use information that was gathered in a particular way, then it is unethical to gather that information in the first place.', 'It is unethical to encourage people to engage in behavior that could damage the integrity of their personal relationships.']