Five Jobs Are Ready for Processing at Time Zero Through

Multiple Choice

Five jobs are ready for processing at time zero through a workstation. The details of the processing time and the due date of completion is provided in the following table.
$\begin{array} { | l | l | l | } \hline \text { Job } & \text { Processing Time (days) } & \text { Due Date } \\\hline \mathrm { A } & 8 & 12 \\\hline \mathrm { B } & 4 & 9 \\\hline \mathrm { C } & 3 & 6 \\\hline \mathrm { D } & 7 & 7 \\\hline \mathrm { E } & 5 & 20 \\\hline\end{array}$
Using the shortest processing time (SPT) rule, it can be concluded that the average flow time for these five jobs is _____.

A) more than 8 but less than or equal to 10 days.
B) more than 10 but less than or equal to 12 days.
C) more than 12 but less than or equal to 14 days.
D) more than 14 but less than or equal to 16 days.