Decision D$6,$ which has three possible choices $($X$,$ Y$,$ or Z$),$ must be made in year $3$ of a $6-$year study period

in order to maximize $E(PW).$ Using an MARR of $16\%$ per year, the investment required in year $3,$ and the

estimated cash flows for years $4$ through $6,$ determine which decision should be made in year $3.$