The correct answer is: B. Double clicking the cell to edit it in-place.
To edit a cell in Excel, you can double click on the cell to enter edit mode. You can then type in the new value or formula for the cell. When you are finished editing, press Enter or click on another cell to exit edit mode.
Option A is incorrect because clicking the formula button will not edit the cell. The formula button is used to insert a formula into a cell.
Option C is incorrect because selecting Edit > Edit Cell from the menu will also not edit the cell. This menu option will open the Edit Cell dialog box, which allows you to edit the cell’s contents, but it does not edit the cell in-place.
Option D is incorrect because it is not a valid option.