Final answer:
In Saunders's story, the man and his grandson are exposed to c. individualized audio messages as they walk down the street.
Step-by-step explanation:
In Saunders's story, the advertising tool used as a man and his grandson walk down the street is an individualized audio message. In the 1920s, radios became a common feature in American homes, and advertisers took advantage of this new medium by broadcasting advertisements over the radio. Unlike print media, radio advertisements could reach anyone within listening distance. This allowed advertisers to tailor their messages to a broad audience, but they had to be more conservative and careful not to offend anyone.