Show me the steps to solve $10.$ Ravi wants to show invoices for security plans only and want to make the PivotTable easier to interpret. Modify the PivotTable as follows to meet Ravi's requests:

a$.$ Use Unpaid as the column heading in cell C$4.$

b$.$ Use Paid as the column heading in cell D$4.$

c$.$ Filter the PivotTable to display invoices for the Security plan and Security plan for apartment building contract types.