Non-price determinants shift the demand curve for public transport

Steps:

• Assume the demand curve is for public transport; D2 indicates a rightward shift (increase in demand).
• Recall that demand shifts from changes in income, tastes, related goods prices/quality, expectations, or buyer numbers—not own price.
• Evaluate options: own-price changes cause movement along the curve; substitute changes or own quality affect shifts.
• Identify the option that increases demand via a non-price factor.

Why D is correct:

• D increases demand through a non-price determinant like higher income for a normal good, per the law of demand's ceteris paribus shifters.

Why the others are wrong:

• A: Banning car running costs likely lowers substitute costs, shifting demand left.
• B: Rising own price causes movement up along the curve, not a shift.
• C: Declining own quality shifts demand left (decrease).

Not enough information on exact D content, but it fits as the shifter. Final answer: D