Which of the following objects always require an activity from you before they can be built?

The correct answer is the multi-target application. This object specifically requires an activity before it can be built because it involves multiple components, such as the integration of database artifacts, server-side logic, and potentially client-side application design. A multi-target application in SAP HANA must be evaluated based on the specific structure and functionality desired, which necessitates deliberate planning and configuration steps before actual construction can take place.

In contrast, synonyms definitions, SAP HANA database modules, and logical schema definitions are primarily setup activities that can be defined without necessarily involving broader application architecture or dependencies. They may require configuration, but they don't necessitate the multifaceted planning and integration that a multi-target application does.