Are consumers only interested in making themselves as well off as possible in a material sense? consumers are a. also concerned with fairness as exemplified by donations to charity. b. only concerned with their own utility as exemplified by social influences having no effect on decision-making. c. also concerned with fairness as exemplified by only tipping in restaurants that will be visited again. d. only concerned with their own utility as exemplified by network externalities. e. only concerned with their own financial well-being as exemplified by only parting with money when required.