What action must be taken to add a column to the left of the selected cell?

To add a column to the left of the selected cell, right-clicking the column header and choosing the Insert option is the appropriate action. This method works because right-clicking a column header targets the entire column, allowing you to insert a new column directly adjacent to it. When you choose Insert in this context, the new column is placed to the left of the highlighted column, accommodating any existing data without disrupting it.

Other options, while related to inserting or creating new elements in a spreadsheet, do not specifically allow for the insertion of a column to the left of the selected cell. For instance, right-clicking the cell itself typically only provides options related to cell content or formatting, rather than structural changes to the grid. Similarly, using the Home Tab generally involves more menu navigation and options that may not directly lead to adding a column in the manner described. Lastly, selecting a cell and pressing Ctrl + N is not a standard shortcut in most spreadsheet applications for adding columns and typically leads to a new document. Therefore, right-clicking the column header is the most straightforward and efficient action for adding a column to the left of a selected cell.