Final answer:
The correct answer is option A: Average quarter-hour figure, which is the estimated total number of different people who listen to a radio station for a minimum of five minutes in a quarter-hour period within a reported daypart.
Step-by-step explanation:
The correct answer to the question is option A: Average quarter-hour figure.
Average quarter-hour figure is the estimated total number of different people who listen to a radio station for a minimum of five minutes in a quarter-hour period within a reported daypart. It is a measurement used to assess the popularity and reach of a radio station by determining the average number of listeners during a specific time period.