The beam is subjected to an internal moment of M=100kN*m, determine the bending stress developed at points A, B, and C. Sketch the bending stress distribution on the cross sections.
a) 150 MPa, 100 MPa, 50 MPa
b) 50 MPa, 100 MPa, 150 MPa
c) 100 MPa, 150 MPa, 50 MPa
d) 100 MPa, 50 MPa, 150 MPa