Which statement best describes the GROUPING function?

Which statement best describes the GROUPING function?

A.
It is used to form various groups to calculate total and subtotals created using ROLLUP
and CUBE operators.

B.
It is used to identify if the NULL value in an expression is a stored NULL value or created
by ROLLUP or CUBE.

C.
It is used to set the order for the groups to be used for calculating the grand totals and
subtotals.

D.
It is used to specify the concatenated group expressions to be used for calculating the
grand totals and subtotals.