Answer: B. Outlier
Explanation:
An outlier is an extremely large or extremely small data value in a data set such that it appears far from the other data points when we plot data points on scatter plot or box plot.
Thus, the data point that is the farthest from other data points when the box plot is NOT symmetrical is Outlier.
Its presence affects the value of mean directly. So when a data set have outliers , we prefer Median(Mid value of a data set) as the best measure of central tendency because existence of outliers does not effect Median .
Hence, the correct option is B. Outlier.