Pressure from liquid weight over base area

Steps:

• Calculate base area: A = π (d/2)² = π d² / 4.
• Force on base: weight of liquid = mg.
• Pressure P = force / area = mg / (π d² / 4) = 4mg / π d².
• Depth h is not needed, as pressure depends on total weight and area.

Why C is correct:

• Matches formula P = mg / A, where A = π d² / 4, per hydrostatic pressure definition.

Why the others are wrong:

• A: Omits factor of 4 from radius in area, underestimates pressure.
• B: Includes h unnecessarily; pressure uses total mass, not density times h.
• D: Adds h and factor of 4, confusing weight with ρgh form.

Final answer: C