The correct answer is B because the CUI banner marking is a document-level marking and must reflect the CUI contained in the document, not merely the CUI on one page or only the cover. The CUI marking rule states that CUI banner markings may include the CUI control marking, category or subcategory markings, and limited dissemination controls. It also states that CUI Specified category or subcategory markings that pertain to the information in the document must be included in the banner marking. Most importantly, the content of the CUI banner marking must apply to the whole document, inclusive of all CUI within the document, and must be the same on each page of the document that includes CUI. Option A uses “highest level” language, which is more characteristic of classified-information marking logic and is not the cleanest CUI rule. Options C and D are wrong because they confine special category/subcategory marking to the cover page or only selected pages, while the CUI banner marking operates at the document level. Reference/topics: CUI Registry, CUI banner marking, CUI category/subcategory markings, CUI Specified.