Combined Supply and Demand Shifts Steps:

• Rising production costs decrease supply, shifting the supply curve left (higher price, lower quantity ceteris paribus).
• Consumer shift to vegan diet decreases demand, shifting the demand curve left (lower price, lower quantity ceteris paribus).
• Both leftward shifts reduce equilibrium quantity unambiguously.
• New equilibrium occurs at the intersection of the shifted curves, typically showing lower quantity and indeterminate price change.

Why A is correct:

• A shows the equilibrium after both leftward shifts, consistent with the law of supply and demand where quantity falls due to reduced supply and demand.

Why the others are wrong:

• B: Reflects only supply shift (ignores demand decrease, overstates price rise).
• C: Reflects only demand shift (ignores supply increase, understates price effect).
• D: Shows no change or opposite shifts (contradicts both cost rise and diet trend).

Final answer: A