John is trying to decide how to divide his time between his job as a stocker in the local grocery store, which pays $7 per hour for as many hours as he chooses to work, and cleaning windows for the businesses downtown. He makes $2 for every window he cleans. John is indifferent between the two tasks, and the number of windows he can clean depends on how many hours he spends cleaning in a day, as shown in the table below:Hours PerDay CleaningWindowsTotal Numberof WindowsCleaned0017211314416517What is the lowest price per window that John would be willing to accept to spend 4 hours per day cleaning windows?

A. $2
B. $11
C. $3.50
D. $7

Answer: C