What is the primary purpose of a data warehouse? 

Answer options:

A. to provide answers to complex queries that rely on data from multiple sources
B. to provide transformation services between source and target data stores
C. to provide read-only storage of relational and non-relational historical data
D. to provide storage for transactional line-of-business (LOB) applications

C

Consider using a data warehouse when you need to keep historical data separate from the source transaction systems for performance reasons. Data warehouses make it easy to access historical data from multiple locations, by providing a centralized location using common formats, keys, and data models. Query both relational and nonrelational data. Incorrect Answers: D: Data warehouses don`t need to follow the same terse data structure you may be using in your OLTP databases. Reference: https://docs.microsoft.com/en-us/azure/architecture/data-guide/relational-data/data-warehousing