Final answer:
A timely advertisement that shortens a consumer's information search is considered a marketer-dominated source, as it is controlled directly by the company or brand for promotional purposes.
Step-by-step explanation:
Devin's information search was shortened by a perfectly timed advertisement, which is a b) Marketer-dominated source. This classification refers to any channel of information typically controlled by marketers, such as advertisements, company websites, salespeople, and promotional materials. Unlike personal or family sources, which come from individuals' interpersonal networks, or consumer-controlled sources that are managed by consumers themselves, a marketer-dominated source is directly managed by the company or brand looking to promote its products or services.