Final answer:
To add buttons for reports that are not currently open in the Add and Remove Reports window, you can right-click and select Add.
Step-by-step explanation:
In the Add and Remove Reports window, you can add buttons for reports that are not currently open by right-clicking and selecting Add. This will allow you to choose and add reports that are not already listed in the window.
Shaking the mouse vigorously or using the keyboard shortcut Ctrl+Alt+R will not perform the task of adding buttons for closed reports. These actions are not related to adding reports in this window.
Therefore, option a) Right-click and select Add is the correct choice to add buttons for reports that are not currently open in the Add and Remove Reports window.