Activity E has an optimistic duration of $10$ days, most likely duration of $15$ days, and pessimistic duration of $25$ days. What is the expected duration of Activity E using the PERT formula?Select one:A$\mathrm{.}17$ daysB$\mathrm{.}10$ daysC$\mathrm{.}15$ daysD$\mathrm{.}25$ days