Which option best describes a "project-based" voucher?

Project-based vouchers refer to a type of housing assistance where the subsidy is linked to specific units within a housing development, rather than being tied to the individual tenant. This means that the assistance is designated for particular properties or projects, allowing a consistent funding stream for those units, which can help ensure that they remain affordable for low-income households.

This funding model is designed to increase the availability of affordable housing options by allowing property owners to utilize the subsidy to make their housing developments more financially viable, thereby encouraging the development and maintenance of these properties for use by low-income families.

The other options do not accurately reflect the nature of project-based vouchers: they may pertain to various types of housing assistance but do not capture the essential aspect of project-based funding being tied to specific units or developments.