What must occur if a vehicle's odometer cannot remain at the same mileage after servicing?

The requirement that if a vehicle's odometer cannot remain at the same mileage after servicing is that the odometer should be adjusted to read zero. This is grounded in ensuring transparency and integrity in vehicle mileage reporting. When a vehicle undergoes significant repairs or if the odometer has to be replaced, it is essential for the new odometer to reflect that it is starting fresh, hence the adjustment to zero. This allows subsequent owners or users to have a clear understanding of the vehicle’s true mileage since the last recording was disrupted. Such transparency helps prevent potential fraud, as misleading odometer readings can affect a vehicle's value and the buyer's decision-making process.

In contrast, the other options do not align with the legal requirements or ethical standards typically observed in vehicle sales. For instance, selling the vehicle immediately could be unnecessary and impractical; scrapping a vehicle simply due to an odometer issue is not warranted unless there are more severe operational concerns; and replacing the odometer without notice violates regulations designed to protect consumers by ensuring they are aware of significant changes to the vehicle's history.