Final answer:
For Britney, who is well-informed and environmentally conscious, the Central Route of Persuasion focusing on logical arguments like safety and fuel economy would likely be most effective in guiding her car purchase, over the Peripheral Route which uses less analytical appeals.
Step-by-step explanation:
The type of persuasion that would be the most useful to convince Britney to buy a specific car would likely be the Central Route of Persuasion. This method focuses on logical arguments, such as a car's safety features and fuel economy, which are aspects Britney seems to care about given her educated and environmentally conscious approach.
In contrast, the Peripheral Route of Persuasion relies on positive associations and cues such as celebrity endorsements or emotional appeals, which do not require the audience to be analytical or particularly involved in the processing of the message, so it might be less effective for a well-informed buyer like Britney.