Maximum shear stress in a solid shaft of diameter D and length L twisted through an angle θ is τ. A hollow shaft of the same material and length having outside and inside diameters of D and D/2 respectively is also twisted through the same angle of twist θ. The value of maximum shear stress in the hollow shaft will be

• A. \(\frac{{16}}{{15}}\tau \)
• B. \(\frac{{8}}{{7}}\tau \)
• C. \(\frac{{4}}{{3}}\tau \)
• D. \(\tau\)