We can rent a bike for x cents per minute for the first 15 minutes and then y cents for each additional minute. How much will it cost to rent a bike for z minutes, where z>15?	Choose the most appropriate option:
A) 15x+(z-15)y  B) 15x + zy  C) 15y +(z-15)x  D) x + zy  E) x + (z-15)y
The first 15 minutes cost 15x.   The next (z-15) minutes cost (z-15)y.   The total cost is 15x+(z-15)y.   The answer is 15x+(z-15)y.
<result>A</result>
We can rent a bike for x cents per minute for the first 15 minutes and then y cents for each additional minute. How much will it cost to rent a bike for z minutes, where z>15?