Which of the following statements about data warehouses and data marts are correct? Select all that apply. Explain if incorrect. 

a. A data warehouse is a subset of the enterprise database that focuses on one particular subject or decision area. 

b. The dimension table describes business dimensions of interest, such as customer, product, location, and time, while the fact table contains facts about the business operation. 

c. A star schema represents a multidimensional data model. 

d. A data warehouse is the central repository of data from multiple departments within a business enterprise to support managerial decision making.