The radius of relative stiffness is given by the characteristic equation of _______

• A. \(l=\{\frac{eh^3}{12(1-μ^2 ) k_s}\}^\frac{1}{4}\)
• B. \(l=\{\frac{eh^3}{12(1-μ^4 ) k_s}\}^\frac{1}{4}\)
• C. \(l=\{\frac{eh^3}{12(1-μ^2 ) k_s}\}^\frac{1}{2}\)
• D. \(l=\{\frac{eh^3}{12(1-μ^2 ) k_s}\}^\frac{1}{3}\)