Simultaneous Shifts in Demand and Supply

Steps:

• Good weather boosts peach supply, shifting the supply curve rightward and lowering price for any quantity.
• Good weather also increases demand for peaches, shifting the demand curve rightward and raising price for any quantity.
• The combined rightward shifts increase equilibrium quantity, as both curves move toward higher output.
• Price change is indeterminate, depending on the relative magnitudes of the shifts.

Why D is correct:

• Per supply-demand equilibrium, parallel outward shifts raise quantity definitively but leave price ambiguous without shift sizes (law of supply and demand).

Why the others are wrong:

• A: Quantity rises, not falls; price is uncertain, not guaranteed to fall.
• B: Quantity rises, not falls; price is uncertain, not guaranteed to rise.
• C: Price is uncertain, not guaranteed to rise; quantity rises definitively.

Final answer: D