AT&T Has a Marketing Research Department That Regularly Collects Customer

Multiple Choice

AT&T has a marketing research department that regularly collects customer information from numerous sources including: sales invoices, salesperson expense accounts, warranty cards, etc. This is an example of a firm's:

A) external published secondary source.
B) internal secondary source.
C) external commercial secondary source.
D) tertiary data.
E) None of the above.