Which of the following cannot be built using the Interface Designer?

The correct choice is that decisions cannot be built using the Interface Designer. The Interface Designer in Appian is primarily focused on creating user interfaces such as forms, reports, and dashboards. These components are designed to allow users to interact with data, visualize information, and capture inputs effectively.

Forms are used to collect user input in a structured format, which can be utilized in workflow processes. Reports present data in a way that allows users to analyze information easily, while dashboards compile various reports and metrics to provide a comprehensive overview of performance indicators at a glance.

Decisions, on the other hand, pertain to the business logic or rules that determine the actions taken in response to certain inputs or conditions within an application. Decisions are typically configured in the Decision Designer, a separate component from the Interface Designer. This distinction is important because it highlights that while the Interface Designer focuses on the presentation layer for user interactions, decision-making logic falls under a different domain intended for defining and automating business rules. Thus, the ability to create decisions lies outside the purview of the Interface Designer.