Defines how labels are displayed. Depending on what component wraps it, <apex:chartLabel> gives you options for affecting labels for bar and line series labels, pie chart segments, and axes labels. Note: This component must be enclosed by a data series component (<apex:barSeries>, <apex:lineSeries>, or <apex:pieSeries>) or an <apex:axis> component. 

Answer options:

A. apex:chart
B. apex:include
C. apex:chartLabel
D. apex:messages

C