Option D is correct. The scenario describes combining multiple complementary data sources into one comprehensive dataset. That is data blending. Last-mile ETL is usually project-specific final transformation near the end of an analytics workflow, while this question emphasizes combining two source datasets for broader ongoing team use. The current official Databricks exam guide describes the same kind of capability as creating unified datasets by joining data from multiple sources. That aligns with the concept of data blending. Reference: Databricks Certified Data Analyst Associate Exam Guide.