The Owner/operator of the Local Franchise of Handyman, Inc If He Uses the Shortest Processing Time First Priority Rule

The owner/operator of the local franchise of Handyman, Inc., has four jobs to do today, shown in the order they were received: $$\begin{array} { l c c } \text { Job } & \text { Processing } & \text { Due } \\&\text { Time (hrs) } & \text { (hrs from now) } \\\hline \mathrm { W } & 4 & 4 \\\mathrm { X } & 3 & 5 \\\mathrm { Y } & 2 & 2 \\\mathrm { Z } & 1 & 1\end{array}$$ If he uses the shortest processing time first priority rule to schedule these jobs, what will be the average completion time?

A) 7.5 hours
B) 5 hours
C) 3 hours
D) 2.5 hours
E) 2 hours