A Copper Tube with Wall Thickness of 8 Mm Must $60 \mathrm{~mm}$

A copper tube with wall thickness of 8 mm must carry an axial ten- sile force of 175 kN. The allowable tensile stress is 90 MPa. The minimum
Required outer diameter is approximately: (A) $60 \mathrm{~mm}$
(B) $72 \mathrm{~mm}$
(C) $85 \mathrm{~mm}$
(D) $93 \mathrm{~mm}$