What triggers a downgrading of classification levels?

The correct choice for triggering a downgrading of classification levels is a change in circumstances. This is because classification levels are often determined by the sensitivity of the information and the potential impact of its disclosure. As situations evolve, the original rationale for keeping particular information classified may no longer apply. For instance, if the information is no longer sensitive due to advancements in technology, shifts in national security, or sufficient time passing since its classification, authorities may review and decide to lower the classification level accordingly.

This process ensures that classified information is managed appropriately and aligns with current operational or security needs. The other options may pertain to different aspects of information security or disclosure but do not define the specific trigger for downgrading classification levels like a change in circumstances does.