A circular shaft is subjected to the combined action of bending, twisting and direct axial loading. The maximum bending stress \[\sigma \] maximum shearing stress \[\sqrt{3\sigma }\] and a uniform axial stress \[\sigma \](compressive) are produced. The \[\sigma \] maximum compressive normal stress produced in the shaft will be:

• A. 3\[\sigma \]                               
• B. 2\[\sigma \]         
• C. \[\sigma \]                                 
• D. Zero