Four cuboids with the same lengths, breadths and heights are submerged in water. As shown, vertical rods keep the cuboids at the same depth and in matching orientations. Water has density $\rho$. Cuboid W is made from a material with density $4\rho$. Cuboid X is made from a material with density $2\rho$. Cuboid Y is made from a material with density $\rho$. Cuboid Z is made from a material with density $0.5\rho$. Which option is correct?
- AThe upthrust of the water on each of the cuboids is the same.
- BThe upthrust of the water on W is twice the upthrust of the water on X.
- CThe upthrust of the water on X is twice the upthrust of the water on W.
- DThe upthrust of the water on Y is zero.