A passenger has a briefcase which he finds difficult to hold while travelling in a crowded commuter train. Mark who has a seat to himself proposes that the passenger pass the briefcase to him so that he can stand comfortably. Mark does this so that the next time he is in the position of the passenger he would be helped in the same manner. The above incident serves as an example of: options: an informal social contract. natural rights. the invisible hand. utilitarian sacrifice. veil of ignorance.