What is a well informed, but often neglected, source of free marketing data?

 " college professors " .

Assuming that the answer choices are:

— Infomercials

— College professors

— Secondhand textbooks

— PR firms   ;

The best — and correct — answer is:  "college professors" .

D. Create a dashboard and add filters for users, opportunities, accounts, and cases.

Explanation:

From the question, we are informed that the sales manager at Universal Containers would like a dashboard so as to be able to view each of the sales representative's opportunities, accounts, and related cases.

Based on the above scenario, the recommended solution will be to create a dashboard and add then add the filters for users, accounts, opportunities, and cases. When these are done, it'll be easier for the sales manager to view the details of the sales representative.