Correct option is C
The correct answer is (c) $A1.
A mixed cell reference in Excel refers to a reference where one part of the cell reference is absolute (fixed) and the other part is relative (changes when copied).
In $A1, the column A is absolute (fixed), and the row 1 is relative (can change when copied across rows).
This allows the column reference to remain fixed, but the row reference can change when the formula is copied to other rows.
Information Booster:
$A$1 is an absolute reference, where both the column and row are fixed and do not change when copied.
A1 is a relative reference, meaning both the column and row can change when the formula is copied.
=SUM(A1:A5) is an example of a range reference, not a cell reference type.