At a point in the web of a girder, the bending and the shearing stresses are 90N/mm2 (tensile) and 45 N/mm2 respectively. The principal stresses are

• A. 108.64 N/mm2 (tensile) and 18.64 N/mm2 (compressive)
• B. 107.60 N/mm2 (compressive) and 18.64 N/nn2 (tensile)
• C. 108.64 N/mm2 (compressive) and 18.64 N/mm2 (tensile)
• D. 0.64 N/mm2 (tensile) and 0.78/mm2 (compressive)