Final answer:
To establish a contextual relationship between single value properties, a Page Group should be used as it categorizes data records based on key values, allowing single value properties to be contextually related.
Step-by-step explanation:
When you need to establish a contextual relationship between single value properties, the mode that should be used is a Page Group. A Page Group is a collection of pages where each page holds data records that are categorized based on one or multiple key values. This allows for a contextual relationship to be established among single value properties that fall under a certain category.
A Page List is a list of pages that allows you to manage multiple records, but it does not support the idea of keys and categories like a Page Group. The Value Group is not suitable either, as it is used to hold lists of values, not single value properties with contextual relationships. Lastly, a Page is used to represent a single data structure and its properties, but does not inherently handle multiple contextual relationships.