A Publisher Needed One of Its Best-Selling Authors to Fly

A publisher needed one of its best-selling authors to fly from his home in Richmond,Virginia,to Chicago,Illinois,in order to start a publicity campaign for the author's new book.The author could have taken a flight to Detroit,Michigan,changed planes,and then flew on to Chicago for about half the price of a non-stop flight from Richmond to Chicago.However,he chose the non-stop flight.He became less price sensitive because of

A) the availability of substitutes.
B) the fact that someone else was paying the bill.
C) the significance of the end benefit.
D) the size of the total expenditure.
E) the sunken investment he had made.