We can rent a car for x dollars per day for the first 3 days and then y dollars for each additional day. How much will it cost to rent a car for z days, where z>3?	Choose the correct answer
A) x + zy	B) 3y+(z-3)x	C) 3x + 3zy	D) 3x+(z-3)y	E) 3x + zy
The first 3 days cost 3x.   The next (z-3) days cost (z-3)y.   The total cost is 3x+(z-3)y.   The answer is 3x+(z-3)y.
<result>D</result>
We can rent a car for x dollars per day for the first 3 days and then y dollars for each additional day. How much will it cost to rent a car for z days, where z>3?