Q. In which scenario would you use the ROLLUP operator for expression or columns within a GROUP BY clause?

(A) to find the groups forming the subtotal in a row

(B) to create group-wise grand totals for the groups specified within a group by clause

(C) to create a grouping for expressions or columns specified within a group by clause in one direction, from right to left for calculating the subtotals

(D) to create a grouping for expressions or columns specified within a group by clause in all possible directions, which is cross- tabular report for calculating the subtotals