Question

which symbol is used to indicate that a formula may contain an error?
○ green triangle in upper-left corner of cell
○ an orange circle below the formula result
○ green triangle with question mark inside
○ a wavy purple arrow above the formula result

Explanation:

In spreadsheet software (like Excel), a green triangle in the upper - left corner of a cell is used to indicate that a formula may contain an error (such as a potential error in the formula's logic, reference, etc.). The other options do not correspond to the indicator for formula errors. The orange circle, green triangle with question mark, and wavy purple arrow are not the standard indicators for formula errors in spreadsheets.

Answer:

A. green triangle in upper - left corner of cell