Buckling of the compression flange of a girder, without transverse stiffeners, can be avoided if (with standard notations)

• A. \(\frac{d}{{{t}_{w}}}\le 345\epsilon _{f}^{2}\)
• B. \(\frac{d}{{{t}_{w}}}\le 270\epsilon _{f}^{2}\)
• C. \(\frac{d}{{{t}_{w}}}\le 345{{\epsilon }_{w}}\)
• D. \(\frac{d}{{{t}_{w}}}\le 250{{\epsilon }_{w}}\)