Figure: The Gains from Trade Price $7 6 5 4 3 2 1 0 D D 5 10 15 20 25 30 35 40 45 50 55 Quantity S 13. (Figure: The Gains from Trade) Examine the figure The Gains from Trade. When demand increases from D to D2, equilibrium total surplus: A) decreases by $10. B) increases by $12.75. C) decreases by $15. D) increases by $27.50.