A project manager is managing an industrial project using a hybrid approach. The project team has estimated that a work package will most likely require $5$ days to complete. If everything goes well, it could take only $3$ days. However, in the worst$-$case scenario, it might take up to $13$ days to complete. So$,$ the team has decided to opt for the PERT method to set a final estimate. What is the expected duration of the work package using the PERT method?

$6$ days

$5$ days

$8$ days

$7$ days