A data warehouse should be designed to meet three criteria. If the data warehouse is using a copy of data from the active databases that the company uses in its day$-$to$-$day operations, so that data warehouse must pull data from the existing databases on a regular, scheduled basis, what is this criterion? Select one: a$.$ The data is standardized. b$.$ The data is time$-$variant. c$.$ Data warehouse uses virtualization. d$.$ Data warehouse uses non$-$operational data. e$.$ Data warehouse uses operational data.