A Brass Pipe Is Twisted by Torques T = 800 $L=2.1 \mathrm{~m}, d_{1}=38 \mathrm{~mm}, \text { and } d_{2}=56 \mathrm{~mm}$

A brass pipe is twisted by torques T = 800 N . m acting at the ends causing an angle of twist of 3.5 °. The pipe has the following properties: $L=2.1 \mathrm{~m}, d_{1}=38 \mathrm{~mm}, \text { and } d_{2}=56 \mathrm{~mm}$ . The shear modulus of elas-
Ticity G of the pipe is approximately: (A) $36.1 \mathrm{GPa}$
(B) $37.3 \mathrm{GPa}$
(C) $38.7 \mathrm{GPa}$
(D) $40.6 \mathrm{GPa}$