Designing the data storage architecture is an important activity in system design. There are two main types of data storage formats: files and databases. Files are electronic of data that have been optimized to perform a particular transaction. There are several types of files that differ in the way they are used to support an application. （　） store core information that is important to the business and , more specifically , to the application , such as order information or customer mailing information. （请作答此空） contain static values , such as a list of valid codes or the names of cities . Typically, the list is used for validation. A database is a collection of groupings of information that are related to each other in some way. There are many different types of databases that exist on the market today. （　） is given to those databases which are based on older , sometimes outdated technology that is seldom used to develop new applications . （　） are collections of records that are related to each other through pointers In relational database , （ 　） can be used in ensuring that values linking the tables together through the primary and foreign keys are valid and correctly synchronized.

A. Master files

B. Look-up files

C. Audit files

D. History files