Create a formula from the value in a cell

[Albireo]

Suppose that in Cell A1 there is a numerical value (for example 15)
In cell B5, the contents of C15 should be displayed.
It’s simple - the formula =C15 is written in the cell B5
But I want to use the number found in Cell A1 (15) in my formula.
If the value in A1 is changed to 16, the value in cell C16 should show in cell B5

How should the formula in cell B5 be written for the number of the row to be retrieved from Cell A1?
Is it possible?

[JohnSUN]

Try any

=INDIRECT("C"&A1)
=INDEX(C:C;A1)
=OFFSET(C1;A1-1;0)