Which of the following describe data warehouses? (select all that apply)

a) has a purpose to combine strategic information into a single repository in such a way that people who need that information can make decisions and undertake business analysis.
b) a subset of information from a datamart.
c) a process that transforms data from internal and external databases using a common set of enterprise wide definitions.
d) supports business analysis activities and decision making tasks.
e) a logical collection of information gathered from many operational databases.