The natural frequency of transverse vibration of a massless beam of length \(L\) having a mass \(m\) attached at its midspan is given by ( \(E I\) is the flexural rigidity of the beam)

(a) \(\left(\frac{m L^{3}}{48 E I}\right)^{\frac{1}{2}} \mathrm{rad} / \mathrm{s}\)

(b) \(\left(\frac{48 m L^{3}}{E I}\right)^{\frac{1}{2}} \mathrm{rad} / \mathrm{s}\)

(c) \(\left(\frac{48 E I}{m L^{3}}\right)^{\frac{1}{2}} \mathrm{rad} / \mathrm{s}\)

(d) \(\left(\frac{3 E I}{m L^{3}}\right)^{\frac{1}{2}} \mathrm{rad} / \mathrm{s}\).