When Using Subtotal,what Does the 4th Button of the Outline

Multiple Choice

When using subtotal,what does the 4th button of the outline levels do?

A) Collapses the outline to display the grand total only
B) Displays subtotals by the main subtotal category and the grand total
C) Displays the entire list
D) Displays subtotals by the main subtotal category,the secondary
Subtotal category,and the grand total