A Cast Iron Pipe $\left(L=12 \mathrm{~m} \text {, weight density }=72 \mathrm{kN} / \mathrm{m}^{3}\right. \text {, }$

A cast iron pipe $\left(L=12 \mathrm{~m} \text {, weight density }=72 \mathrm{kN} / \mathrm{m}^{3}\right. \text {, }$ $\left.d_{2}=100 \mathrm{~mm} \text {, and } d_{1}=75 \mathrm{~mm}\right)$ is lifted by a hoist. The lift points are 6 m apart. The maximum bending stress in the pipe is approximately: (A) $28 \mathrm{MPa}$
(B) $33 \mathrm{MPa}$
(C) $47 \mathrm{MPa}$
(D) $59 \mathrm{MPa}$