What does the term "Sell-Up" refer to in the context of rental income strategies?

The term "Sell-Up" in the context of rental income strategies refers to the practice of offering customers a larger vehicle. This strategy aims to enhance customer satisfaction by providing them with better options that may lead to an increased rental fee. By upselling, rental companies can encourage customers to upgrade to a larger or more premium vehicle, which often comes with higher pricing due to added features or comfort. This approach not only increases rental income but can also improve the overall customer experience as they may appreciate the additional space or enhancements offered.

The other options do not align with the "Sell-Up" strategy, as they involve either downgrading vehicle options or altering terms of the rental in ways that don't focus on enhancing or upgrading the customer’s choice.