Answer this multiple choice question: A company is designing a product layout for a new product. It plans to use this production line eight hours a day in order to meet projected demand of $480$ units per day. The tasks necessary to produce this product:

TASK PREDECESSOR TIME$($seconds$)$

u $30$

v u $30$

w u $6$

x w $12$

y x $54$

z v$,$ y $30$