Buoyant force equals net upward pressure force Steps:

• Pressure force downward on top surface: p1 × A
• Pressure force upward on bottom surface: p2 × A
• Net upthrust: upward force minus downward force = (p2 × A) - (p1 × A)
• For fully immersed cylinder, side forces cancel; upthrust = (p2 - p1)A

Why A is correct:

• Equals weight of displaced water per Archimedes' principle, as (p2 - p1) = ρgh and A × h = volume.

Why the others are wrong:

• B: Reverses pressures, yielding downward (negative) force, opposite to upthrust direction.
• C: Subtracts weight W, giving net force instead of buoyant force alone.
• D: Wrong pressure difference sign and subtracts W, incorrect for upthrust.

Final answer: A