An operator is assigned to service four machines that have an expected downtime of 50 percent. When running, each machine can produce 60 units/hour. The operator is paid $20.00/hour, and a machine costs $50.00/hour to run. How much is total expected cost (TEC) per piece for one operator? OA $178 OB $1 25 O C $0 60 O D.$0 98 OE $0.72