The correct answer is: A. $
The dollar sign ($) is used in Excel to specify fixed columns or rows in a formula. For example, if you have a formula in cell A1 that references cells B1 and C1, you can use the dollar sign to specify that you want to reference those cells even if you copy the formula to another cell. To do this, you would type the formula as follows:
=A1*$B$1
The dollar signs will tell Excel to reference cells B1 and C1, even if you copy the formula to another cell.
The other options are incorrect because they do not specify fixed columns or rows in a formula. The asterisk (*) is used to multiply values, the percent sign (%) is used to calculate percentages, and the ampersand (&) is used to concatenate text.
I hope this helps! Let me know if you have any other questions.