Jack's Convenience Store is open for 20 hours a day, Monday through Saturday. There is always one employee in the store. The store employs three full-time employees, who work 40 hours per week and earn $9 per hour. The store also spends $200 per week on each full-time employee's benefits. Their labor contract requires that they earn double-time for any overwork and that any employee who works 30 hours or more per week be given full benefits. The store is considering expanding its hours to 24 hours per day, Monday through Saturday, and 16 hours on Sunday.

Which of these is the stores least-costly alternative?

a. have it's current employees work overtime b. hire a new 20-hour-per-week employee and have its current employees work overtime

c. hire two new 20-hour-per-week employees at the current wage

d. hire a new full time employee