Hi Michelle

"This file" means a particular file?
Generally:
The first option is the correct one, the others are just there to confuse user.
With the first option you can manage any freezing:
- scroll your spreadsheet the way that column A and row 1 is visible
- select cell B2
- in clicking the first option it either removes freezing or enables freezing. In enabling it will freeze all columns left and all rows above the selected cell.

In selecting any cell and enabling the first option of freezing the rule above is applied.