Final answer:
For an advertiser with a limited budget aiming at a local target audience, local radio is the recommended option due to its cost-effectiveness and localized reach. Thus, the correct option is 4.
Step-by-step explanation:
If an advertiser has a limited budget and wants to reach a well-defined target audience in a local market area, the most suitable choice would be local radio. Despite the decline in radio advertising's effectiveness at a national level, local radio still holds value for localized impact, particularly in the realm of local elections or small market targeting. Network television, network radio, and superstations have broader reach and are typically more expensive, lessening their appeal to advertisers with restricted budgets.
A local station that broadcasts national network programming is known as an affiliate. These affiliates allow national networks to reach local audiences, but for an advertiser focused on a niche market, the wide distribution is less advantageous. Local radio, by contrast, can target listeners based on specific demographics unique to the community, such as musical preference, racial or ethnic backgrounds, languages, and interests.