What document is missing that prevents the approval of Stan's adjustment of status application?

The underlying basis for adjustment is a crucial document for the approval of an adjustment of status application. In U.S. immigration law, individuals seeking to adjust their status to that of lawful permanent resident must demonstrate eligibility through an appropriate underlying basis, such as family relationships, employment sponsorship, or refugee/asylee status. This basis establishes the legal foundation for the application and confirms that the applicant meets the necessary criteria under immigration law.

Without this underlying basis, USCIS cannot determine the applicant's eligibility for adjustment of status. This component of the application process ensures that all adjustments are built on valid and recognized claims to lawful permanent residency.

The other options do not directly address this fundamental requirement. Immediate relative adjustment and preference relative adjustment refer to categories under which individuals may qualify for adjustment but do not themselves serve as foundational documents. Similarly, underlying adjustment for change does not accurately capture the necessary requirement of an underlying basis for the adjustment process. Therefore, lacking the underlying basis for adjustment represents a key deficiency that can prevent the approval of Stan's application.