The tube is made from a material having an allowable shear stress of τ(allow) = 80MPa. The inner radius is 26mm and the outer radius is 30mm. Determine the maximum allowable intensity τ(0) of the shearing force applied to the tube.
a) 7542.80N/mm²
b) 6523.08N/mm²
c) 8301.59N/mm²
d) 9147.40N/mm²