Bobby needs a business law book. he hears that gwen has one for sale. bobby asks his girlfriend, susie, to buy it for him from gwen if susie can get it for under $40. susie sees gwen and asks if gwen will sell the book for $30, and gwen agrees. susie does not mention that the book is for bobby although all the parties were on good terms, and the identity of the buyer should not have affected susie's agreement. later, however, polly agrees to give bobby her used business law book. bobby tells susie that he no longer wants the book. susie tells gwen about the situation with bobby. gwen replies that she does not care if bobby wants the book or not. gwen says that she passed up a couple of opportunities to sell the book because she thought she already had it sold and that she wants her money from either gwen or bobby - she doesn't care who pays. what type of principal is bobby?