Step 1: Clarify the goal.
The Mayor wants owners and drivers to actively care about passenger comfort. The best policy would be one that directly links passenger comfort with drivers’/owners’ incentives or consequences.
Step 2: Assess the options.
- (A) Random police inspections — While inspections may check compliance, they are irregular, external, and may not directly reflect real passenger experiences. Limited effectiveness.
- (B) Bank loans for car ownership — Ownership may indirectly improve maintenance and comfort, but it does not guarantee that drivers will prioritize passenger comfort.
- (C) Licensing air-conditioned taxis — Helps a certain group (wealthier passengers) but does not ensure overall improvement in comfort standards across all taxis.
- (D) Feedback system linked to license renewal — Strongest mechanism. It directly ties passenger comfort ratings to the drivers’/owners’ ability to continue operating. This creates a continuous incentive to improve comfort for all passengers.
- (E) Doubling metered rates — Provides more income to owners but does not guarantee that money will be reinvested in passenger comfort.
Step 3: Conclude.
The most effective and reliable policy is (D), since it creates accountability by linking service quality with the license to operate.
\[
\boxed{\text{Correct Answer: (D)}}
\]