PeTu (a) The cell references containing values to be used for calculations passed
to the function are called​

Arguments

Explanation:

When input is passed to a function, the input is referred to as an argument.

And the syntax is:

Function_Name(argument_1, argument_2...,argument_n)

I'll answer this question using the following instance:

The following instruction written in cell C3:

=SUM(C1,C2)

The above instruction in Excel adds up the content of cell C1 and C2, and the result is saved in C4.

If C1 = 2, C2 = 3

C3 will be:

Using:

Function_Name(argument_1, argument_2...,argument_n)

The arguments of =SUM(C1,C2) are C1 and C2.

Hence, the term that answers this question is: argument