The fоllоwing is а prоduct structure tree for а toy cаlled zigzag robot (Z-robot). The manufacturer receives an order of 50 units of Z-robot that should be ready in week 10. The lead times for the components are Z (2 weeks), A (1 week), B (1 week), C (1 week), D (1 week), and E (3 weeks). None of these items has inventory on hand. Node Parent Level Children Z — 0 A(2), B(4) A(2) Z 1 C(3), D(4) B(4) Z 1 — C(3) A(2) 2 — D(4) A(2) 2 E(2) E(2) D(4) 3 — What is the net requirement for item D?