In order to compare the national retailers' success in selling its brands of digital cameras with the national retailers' success in selling traditional camera equipment, the marketing manager for Sony decided to use the billing information Sony has for these national retailers. This information is fed into spreadsheets formatted in tabular form and updated continuously as accounts change. In doing so, the marketing manager for Sony utilized which one of the following?

A) a rolling audit
B) a functional system
C) an expert system
D) a decision support system
E) a marketing information system

E