A work centre uses an average of 850 parts per day. A standard sized container holds 160 parts. On average it takes .30 days for a contained to complete the circuit from a kanban being received until the container is returned full. If the policy is to use a safety stock of 20% (\% of usage during the lead time), how many kanbans should be used? (rounding up to provide a relatively loose system). Multiple Choice 4 2 3 1