A solid steel bar of circular cross section $($Fig$.3-11)$ has diameter $d=1\mathrm{.}5in,,$ length $L=54in.,$ and shear modulus of elasticity $G=11\mathrm{.}5{10}^6.$ The bar is subjected to torques $T$ acting at the ends.

If the torques have magnitude $TV=150lb-$ft$,$ what is the maximum shear stress in the bar in psi?

a$.5300$

b$.2717$

c$.5\mathrm{.}3$

d$.4530$