For the framing plan shown in the figure, all beam end connections are pinned. All members have continuous lateral braces. The whole floor is $5-$in$.$ concrete slab $($weighing $15$ psf per inch thickness, service dead load$),$ and service live load on the floor is $200$ psf$.($neglect beam self$-$weight$)$ For beam $2($B$2),$ draw a free body diagram and select the lightest W$-$shape of A$572$ Gr$\mathrm{.}50$ steel. Check all flexural and shear limit states