Final answer:
Online Analytical Processing (OLAP) is the tool capable of "drilling up" from detailed data to aggregated higher-level views, enabling the analysis of quantitative data and support for in-depth research.
Step-by-step explanation:
The tool capable of "drilling up" and proceeding from the smallest unit of data to higher levels in data analysis is Online Analytical Processing (OLAP). OLAP allows users to explore quantitative data through a multidimensional data model, facilitating complex analytical calculations, trend analysis, and data mining. This is particularly useful in situations that require in-depth interviews, focus groups, and analysis of content sources, as it supports the collection and manipulation of large volumes of data to unearth patterns and insights.
Meanwhile, Online Transaction Processing (OLTP) is designed more for the efficient processing of transaction-oriented tasks. Extraction, Transformation, and Loading (ETL) are processes used to prepare data for analysis but typically do not involve data exploration by moving up through different levels of aggregation. Lastly, Business Analytics employs various methods and tools, including OLAP, to analyze and interpret business data to make informed decisions.