The function gives the total cost, in dollars, of a phone plan that includes a monthly fee of plus for each minute of talk time used. Which of the following is the best interpretation of ?
If the total cost of the phone plan is , then 60 minutes of talk time were used.
If 200 minutes of talk time are used, then the total cost of the phone plan is .
If the total cost of the phone plan is , then was the monthly fee.
If 200 minutes of talk time are used, then the cost per minute is .
