Demand Shift in Food Market Steps:

• Shoppers' increased buying due to pollution fear raises demand for food.
• Demand curve shifts right from initial equilibrium X.
• At original price, quantity demanded exceeds supply, creating shortage.
• Price rises to new equilibrium with higher price and higher quantity.

Why A is correct:

• A depicts rightward demand shift, raising equilibrium price and quantity per basic supply-demand model.

Why the others are wrong:

• B shows supply increase, lowering price but not matching demand surge.
• C indicates supply decrease, raising price but reducing quantity, opposite of shortage response.
• D reflects demand decrease, lowering both price and quantity, irrelevant to buying increase.

Final answer: A