$2\mathrm{.}1$ What are the failure modes considered when designing steel members for tension? $($select all that apply$)$

a$.$ Torsional buckling

b$.$ Yielding of the gross section

c$.$ Rupture of the net section

d$.$ Yielding of the net section

$2\mathrm{.}2$ Select the most economical beam section listed below that can support a design moment $($ASD$)$ of M$=330$kip$-$ft when the compression flange is continuously braced.

a$.W2455,\frac{M_{px}}{{}_b}=334$kip$-ft,Lp=4\mathrm{.}73ft$

b$.W1865,\frac{M_{px}}{{}_b}=332$kip$-ft,L_p=5\mathrm{.}97ft$

c$.W1287,\frac{M_p}{{}_b}=329$kip$-ft,Lp=10\mathrm{.}8ft$

d$.W1667,\frac{M_{px}}{{}_b}=324$kip$-ft,L_p=8\mathrm{.}69ft$