What describes the applicability of private-sector pronouncements to proprietary funds after November 30, 1989?

Proprietary funds, which are used by governmental entities to report activities that are similar to private-sector businesses, follow different guidelines than governmental funds. After November 30, 1989, private-sector pronouncements became optional for proprietary funds. This means that while proprietary funds can choose to follow these private-sector accounting and financial reporting standards, they are not required to do so.

Additionally, the phrase "Not an option" refers to the fact that certain specific private-sector pronouncements were explicitly not applicable to proprietary funds as per governmental accounting standards. Therefore, both the optional application of certain private-sector standards and the specific exclusions create a scenario where both options represent the correct understanding of how these pronouncements interact with proprietary funds post-1989. Thus, the answer that combines these perspectives captures the full picture of their applicability within proprietary fund reporting.