In the picture, D is an assembly machine which puts together components received from B and C (in a one-to-one ratio). The numbers indicate the capacity of each machine. If all machines are activated continuously (with the possibility of idling when a machine is 'starved'), where would the inventory build up? A: 10 units /hour B: 12 units /hour D: 10 units /hour C: 8 units /hour O between A and B O there would be no inventory build up O between B and D O between C and D