Final answer:
The phrase about newly minted one-hundred-dollar bills emphasizes the freshness and perceived luxury that the new-car-smell spray adds to Ken's old car, changing his experience and mood. The correct answer is It adds an extra sensory detail about the changes in Ken's perception after the car is spritzed.
Step-by-step explanation:
The phrase about the one-hundred-dollar bills in the passage adds an extra sensory detail about the changes in Ken's perception after the car is spritzed. By comparing the smell to the scent of newly minted one-hundred-dollar bills, the author emphasizes the freshness and the perceived luxury that Ken feels has been added to his old car. This phrase enchants the reader with the transformative power of scent, suggesting that it not only refreshes the car but also Ken's experience and mood while driving.