Final answer:
In SAP BW/4HANA live connections, Conditions, Expressions, and Initial layout are supported query features. SAP BW/4HANA Structures and Exit variables are not because of their complexity and reliance on inactive user exits during live data retrieval.
Step-by-step explanation:
In the context of a live connection to SAP BW/4HANA, certain query features are supported. Based on the options provided in the question, the three correct answers are: A. Conditions, which allow users to define specific criteria that data must meet to be included in query results; B. Expressions, which refer to calculated fields or formulas used within the query to manipulate or display data in a specific way; and E. Initial layout, which pertains to the preset configuration of how query results are displayed when first executed, including column order and visibility. However, SAP BW/4HANA structures (Option C) are not supported in a live connection due to their complex nature and potential changes in structure during live data retrieval, while Exit variables (Option D) are also not supported as they are typically tied to user exits that are not active in a live connection scenario.