A linearly elastic plane beam with a rectangular cross-section, as shown in Figure MKC7, is subjected to a bending moment of 100 kNm about its "strong" axis. NAX (mm) 200 Figure MKC7 200 200 1. The maximum normal bending stresses act at the extreme fibres at the top and bottom of the beam section. 2. The second moment of area of the beam cross-section (about NAX), INAX is equal to 106667 cm4. 3. The bending stress has a value of zero on the neutral axis, NAX. 4. The maximum normal bending stress, x, is 37.5 MPa. Which of the statements are true? All of them 1, 3 and 4 only 1, 2 and 4 only 1, 2 and 3 only 2 and 4 only