please explain both answers

The demand for subassembly S is 100 units in week 7 Each unit of Srequires 2 units of T and 1 unit of U Each unit of Trequires 2 units of V, 1 unit of W. and 1 unit of X Finally, each unit of U requires 1 unit of Y and 3 units of Z. One firm manufactures all items. It takes 2 weeks to make S. 2 weeks to make T. 2 weeks to make U. 1 week to make V, 2 weeks to make W. 1 week to make X 2 weeks to make Y, and 2 weeks to make Z. a) Choose the correct product structure . . Level 0 Q S Q a Level 0 s Tas 1 ) U 1 2 V Y Z W) X 2 V2 Will X Y Z . OC. Level 0 a OD. $ Level 0 S Va) 1 Q V 12 ya 2 Y W X Y Z @ 2 T W X Y Z b) Choose the correct time-phased product structure . OB. . OD ZI V V U . Ek TI o os w T w S T G 03 X o a X X x S Y w S Y U Y U 2 U Z N Time in weeks Tune in week Time in weeks Time in wels