A$-9\mathrm{.}2$: Beam ACB has a pin support at A and is supported at $C$ by a steel column with square cross section $)=190$GPa,$b=(42mm$ and height $L=5\mathrm{.}25m.$ The column is pinned at C and fixed at D $.$ The column must resist a loadQ at $B$ with a factor of safety $2\mathrm{.}0$ with respect to the critical load. The maximum permissible value of $Q$ is approximately:

$($A$)3\mathrm{.}0$ kN

$($B$)6\mathrm{.}0$ kN

$($C$)9\mathrm{.}4$ kN

$($D$)10\mathrm{.}1$ kN