A rigid uniform rod $AB$ of length $L$ and mass $m$ is hinged at $C$ such that $AC = L/3$, $CB = 2L/3$. Ends $A$ and $B$ are supported by springs of spring constant k. The natural frequency of the system is given by
- $\sqrt{\dfrac{k}{2m}} \\$
- $\sqrt{\dfrac{k}{m}} \\$
- $\sqrt{\dfrac{2k}{m} } \\$
- $\sqrt{\dfrac{5k}{m}}$