A hollow metallic bob is filled with a liquid. A small hole is drilled just below the centre of gravity of bob so that liquid slowly drops out of it. Water drops out continuously and the bob gets empty of liquid. In this entire process C.G.

Options

A. remains at the centre of the bob throughout.
B. first shifts downwards from centre of the bob, then upwards and returns back to centre when the bob gets completely empty.
C. first shifts upwards from centre of the bob, then downwards and returns back to centre when the bob gets completely empty.
D. keeps moving upward and downward periodically.