Eighty units of end item x are needed at the beginning of week 6, and another 30 units are needed at the beginning of week 8. prepare a material requirements plan for component d. d can only be ordered in whole cases (50 units per case). one case of d is automatically received every other week, beginning in week 1(i. e., week 1,3,5,7). also there are 30 units of b and 20 units of d now on hand. lead times for all items are a function of quality; one week for up to 100 units, two weeks for 101 to 200 units, three weeks for 201 to 300 units, and four weeks for 301 or more units.