Buoyant Force on Fully Submerged Object

Steps:

• Volume of liquid displaced by cylinder: A × X.
• Mass of displaced liquid: ρ × (A × X).
• Weight of displaced liquid: [ρ × A × X] × g.
• Upthrust equals this weight by Archimedes' principle.

Why D is correct:

• It equals ρ A X g, the weight of liquid displaced by the cylinder's full volume A X.

Why the others are wrong:

• A: Lacks A and X; represents neither volume nor force.
• B: Gives force on top face (pressure ρ g H × A); ignores bottom or full volume.
• C: Identical to B, just reordered; still misses X for full displacement.

Final answer: D