One teller has been serving all customers at a local bank branch in a small town of Boston. Customers arrive in a mean of 1/15 hours (or 4 minutes) with a standard deviation of 1/15 hours. The teller spends a mean of 1/20 hours (or 3 minutes) with a standard deviation of 1/20 hours. Customers visit the branch for different tasks, which creates the variability of service times. Some of their requests, such as money withdrawals, take a short time whereas others such as foreign money deposits take long. (Bank Teller) As a part of job enrichment program, the bank teller left the branch for a week and was replaced by his manager. Unfortunately, the branch manager is not familiar with the teller's job and his average service time is twice the teller's average service time. The queue is ___. (Hint: Recalculate utilization.) During the next week, average flow time (W) will __. A. stable, remain the same B. not stable, grow C. stable, grow D. not stable, remain the same