What year did DHS begin requiring policies for safeguarding documents as SSi?

The correct answer is 2005 because that is when the Department of Homeland Security (DHS) took significant steps to formalize policies regarding the safeguarding of sensitive documents classified as Sensitive but Unclassified (SBU), which is often referred to in various contexts as Sensitive Security Information (SSI).

Prior to 2005, while there were existing measures and guidelines for handling sensitive information, the establishment of explicit policies from DHS marked a critical point in ensuring the protection of such documents. This was part of a broader effort to enhance security protocols in response to the evolving landscape of threats post-9/11, thereby formalizing the standards and expectations for safeguarding sensitive information.

It's important to recognize that the years mentioned for the other choices do not line up with the specific timeline of this policy requirement. For example, 2001 is the year of the 9/11 attacks, which triggered a flurry of security updates but did not specifically focus on SSI policies from DHS. Similarly, 2002 and 2007 either preceded or followed key developments in such policies without being directly associated with the introduction of the new requirements by DHS.