A data series to be rendered as bars in a Visualforce chart. At a minimum you must specify the
fields in the data collection to use as X and Y values for each bar, as well as the X and Y axes to
scale against.
Note: This component must be enclosed within an <apex:chart> component. You can have
multiple <apex:barSeries> and <apex:lineSeries> components in a single chart.

A.
apex:barSeries

B.
apex:inputHidden

C.
apex:outputLink

D.
apex:outputField