Correct Answer - Option 2 : Auto-calculation
Concept:
Calculation is the process of computing formulas and then displaying the results as values in the cells that contain the formulas.
Microsoft Excel automatically recalculates formulas only when the cells that the formula depends on have changed. Autocalculation automatically recalculate the whole worksheet if any change is made in a single cell
This is the default behavior when you first open a workbook and when you are editing a workbook.
However, you can control when and how Excel recalculates formulas.