As a Microsoft Fabric Analytics Engineer, you are tasked with designing a comprehensive data analytics solution for a global marketing agency. The agency aims to analyze the performance of their advertising campaigns across multiple channels, including social media, search engines, and display ads, to identify the most effective channels and optimize their ad spend. The solution must adhere to strict data privacy regulations, handle high volumes of data in real-time, and provide actionable insights through intuitive visualizations. Considering these requirements, which of the following steps is the MOST CRITICAL to initiate the planning of the data analytics environment? (Choose one option.)