Charles' utility function is U(x;y)=xy. Anne's utility function is U(x;y)=1000xy. Diana's utility function is xy. Elizabeth's utility function is U(x; y)=-1/(xy+1).Fergie' s utility function is xy-10000. Margaret's utility function is x/y. Philip's utility function is x(y + 1). (the goods x and y are two very expensive goods. We leave you to speculate about what they are.) Which of these persons have the same preferences as Charles?
(a) Everybody except Diana
(b) Anne and Fergie
(c) Anne, Fergie and Elizabeth
(d) None of them
(e) All of them