Question：Consider the price and demand for tickets to travel by sea ferry. The price of travelling by hovercraft (a substitute form of travel) goes up.

　　Which ONE of the following would you expect to happen?

　　A. The demand curve for sea ferry tickets will shift to the right, and their price will go up. More ferry tickets will be sold.

　　B. The demand curve for sea ferry tickets will shift to the right and their price will go down. More sea ferry tickets will be sold.

　　C. The demand curve for sea ferry tickets will shift to the right and their price will go up. Fewer sea ferry tickets will be sold.

　　D. The demand curve for sea ferry tickets will shift to the left, and their price will go down. More sea ferry tickets will be sold.

　　The correct answer is: A

　　As sea ferry tickets and hovercraft tickets are substitute goods, an increase in the price of hovercraft tickets will cause a shift to the right (increase in demand) for sea ferry tickets. Given no change in supply conditions, the consequence will be an increase in the number of sea ferry tickets sold, at a higher price than before.