Lux Ladies, Inc., is a company that specializes in expensive and unusual gifts for all occasions. It keeps a large file of information on all of its regular customers, including names, addresses, and type of gifts they have ordered in the past, and the size and frequency of their orders.
The electronic file which stores this information is a(n):

A. spreadsheet.
B. MP3 file.
C. PERT file.
D. database.