Answer:
c) Right-click and choose "Insert"
Step-by-step explanation:
To add a column header for the calculation column in a one-variable data table in Microsoft Excel, you can perform the following steps:
Right-click on the cell with the calculation formula in the header row of the table
choose the "Insert" option from the context menu.
This will insert a new column, and you can type the header directly in the newly inserted cell.