Final answer:
The number of households in a market area that own a television set is referred to as 'the universe estimate,' which is crucial for understanding the potential audience in media research and advertising.
Step-by-step explanation:
The number of households in a market area that own a television set is referred to as B. the universe estimate. This term is often used in the context of media research and advertising, where it's important to understand the total potential audience to assess the reach or impact of television programs or commercials. With the post-World War II economic boom, television ownership soared from just under 4 million households in 1950 to over 30 million five years later. Today, with almost every U.S. household possessing a television and with viewers spending countless hours watching TV, advertisers and sponsors heavily rely on television as a platform to promote their goods and services, using sophisticated viewer data to target specific market demographics effectively.