The correct answer is b) mode.
The mode is a statistical term that refers to the value that appears most often in a data set. Unlike the mean, which calculates the average, or the median, which identifies the middle value when data is sorted, the mode simply highlights the most common observation. A data set may have one mode, more than one mode, or no mode at all if all values occur with the same frequency. Understanding the mode can be particularly useful in various fields such as marketing and economics when analyzing trends and behaviors.