Formatting of a data label:
A data label in a chart is used to display additional information about a data point. It can be formatted in various ways to enhance the readability and visual appeal of the chart. The formatting options for data labels include:

1. Font: You can change the font type, size, color, and style (bold, italic, underline) of the data labels to make them stand out.

2. Number format: The number format determines how the values are displayed in the data labels. You can choose from options like currency, percentage, scientific notation, and custom formats.

3. Position: Data labels can be positioned inside, outside, or on top of the data points. You can also specify the exact position of the labels manually.

4. Label options: You can choose to display the data labels for all data points, only the top or bottom values, or specific data points selected by criteria.

Name of a data series:
The name of a data series refers to the label or title assigned to a set of related data points in a chart. It helps in identifying and distinguishing different series within the chart. The name can be descriptive and meaningful to provide clarity about the data being represented. For example, in a bar chart comparing sales data of different products, each product can have a unique name as its data series label.

Value of a data point:
The value of a data point represents the numerical data associated with a specific point on a chart. It could be the result of a measurement, calculation, or any other form of data representation. The values of data points are plotted on the chart's axes to create the visual representation of the data. Displaying the values of data points can provide precise information to the viewers and help in accurate analysis of the chart.

Both b and c:
The correct answer is option 'D' because both the name of a data series and the value of a data point can be displayed as data labels in a chart. By enabling the appropriate options in the chart settings, you can choose to show the name of each data series and the corresponding value for each data point in the chart. This allows viewers to easily understand the data being represented and make informed interpretations from the chart. The combination of showing both the name of a data series and the value of a data point as data labels provides comprehensive information and enhances the clarity and effectiveness of the chart.