Tariff Effects on Surpluses Steps:

• Identify world price Pw on horizontal supply; tariff raises domestic price to Pw + Pt, reducing quantity demanded from Qw to Qt.
• Loss in consumer surplus is trapezoid between Pw and Pw+Pt under demand curve, split into rectangle (tariff revenue) and triangles (deadweight losses).
• Government revenue is rectangle: tariff Pt times reduced imports (Qw - Qt).
• In diagram, x-y labels trapezoid for CS loss; x labels rectangle for revenue.

Why A is correct:

• A identifies CS loss as full trapezoid (x-y) and revenue as rectangle (x), per standard tariff analysis where CS loss = revenue gain + DWL.

Why the others are wrong:

• B includes z (one DWL triangle) in revenue, overstating government gain.
• C provides no areas, ignoring both effects.
• D uses y and z (partial DWL only), missing full CS loss and revenue.

Final answer: A