To create a drop-down list, select cell where you want it to be (in this case, cell I2), and in the Data tab on the ribbon, click "Data Validation" in the drop-down option with the same name.

Microsoft Excel: How to Remove a Drop-Down List. Excel's drop-down menus are useful for creating order forms and navigation for larger files like records of sales.

Learn how to create a drop-down list using Data Validation in Excel. Data Validation limits the type of data that can be entered into a cell.