$4\mathrm{.}6-7$ For the column load sketch below and LRFD$,$ select the lightest

section for the following:

a$.$ A W$16$ of ASTM A$992$ steel. Hint: Use Table $6\mathrm{.}2($no W$16$

columns in Table $4-1$a$)$

b$.$ A steel pipe. Hint: Use Table $4-6$

c$.$ A square HSS$.$ Hint: Use Table $4-4$

d$.$ A rectangular HSS$.$ Hint: Use Table $4-3$