The metallic bob of a simple pendulum has the relative densityr. The time period of this pendulum is T. If the metallic bob is immersed in water, then the new time period is given by [SCRA 1998]

• A.            \[T\frac{\rho -1}{\rho }\]
• B.            \[T\frac{\rho }{\rho -1}\]
• C.            \[T\sqrt{\frac{\rho -1}{\rho }}\]                                      
• D.            \[T\sqrt{\frac{\rho }{\rho -1}}\]