In a simple spring mass vibrating system, the natural frequency \(\omega_{n}\) of the system is \((k\) is spring stiffness, \(m\) is mass and \(m_{s}\) is spring mass)

(a) \(\sqrt{\frac{k}{m-\frac{m_{s}}{3}}}\)

(b) \(\sqrt{\frac{k}{m+\frac{m_{s}}{3}}}\)

(c) \(\sqrt{\frac{k}{m+3 m_{s}}}\)

(d) \(\sqrt{\frac{k}{m-3 m_{s}}}\).