Answer: A) people, households, or businesses who are exposed to a media vehicle or message schedule at least once during a given time period.
Explanation: In advertising, reach is the number of people who are exposed to a given medium during an advertising schedule. This differs from the number of people the advertising needs reach to actually achieve a given goal. This is known as effective reach. For example when running an advertisement on a television channel, the reach is the total number of people or households who are exposed to the channel at least once in any specific time period.
This is useful in calculating the effective reach.