You plan to give an on-site presentation. The external display available for your audience is a 42-inch flat panel monitor. You need to ensure that the presentation on the monitor of your computer is duplicated on the external monitor for the audience. What should you do？（）
- AClick the Show my desktop on the external display only option.
- BConfigure the Presentation settings to mirror your desktop on the external display.
- CConfigure the Presentation settings to extend your desktop to the external display.
- DReduce the screen resolution of your primary display to a value equal to the maximum resolution of the external display.