The correct answer is: C. F5
The function key for changing the current period in Microsoft Excel is F5. Pressing F5 will open the Go To dialog box, which allows you to select a specific cell or range of cells. You can also use the Go To dialog box to jump to a specific page in a workbook.
The other options are incorrect. Alt + F2 is a keyboard shortcut for opening the Insert Function dialog box. F2 is a keyboard shortcut for editing the contents of a cell. F6 is a keyboard shortcut for moving the cursor to the next sheet in a workbook.