1. Salesforce Help, Marketing Cloud Intelligence, Data Stream Types in Marketing Cloud Intelligence. This document outlines the various data stream types. It states, "Each data stream type has a main entity, which is the focal point of the data stream type. For example, the main entity of the Ads data stream type is Media Buy." This directly supports options D and E, as the main entity defines the type and its associated, specific measurements. It also implicitly supports B, as the entire concept is based on mapping to entities.
2. Salesforce Help, Marketing Cloud Intelligence, The Marketing Cloud Intelligence Data Model. This resource explains the foundational structure of data within the platform. It details how data is organized into entities, dimensions, and measurements. The documentation clarifies that all incoming data via data streams is mapped to this model, which requires the presence of at least one entity. This directly supports option B.
3. Salesforce Help, Marketing Cloud Intelligence, Generic Data Streams. This page describes how to create data streams for data types that don't have a predefined connector. It shows that users must map their data to entities and define their own measurements, confirming that not all data streams include the Media Buy entity (invalidating A) and that measurements are specific to the data being uploaded (supporting E).