Ice cube of size $100\;cm$ and area of base $(500 m \times 50 m)$ is floating in a tank partially filled with water. The change in gravitational potential energy, when ice melts completely (density of Ice is $900\;kg/m^3$)

Question

$$(a)\;-0.072\;J \quad (b)\;-0.24\;J \quad (c)\;-0.016\;J \quad (d)\;-0.045\;J$$