Final answer:
To sort selected cells by last name in ascending order in Excel, go to Data > Sort > Last Name > Ascending.
Step-by-step explanation:
The correct option to sort the selected cells by last name in ascending order in Excel is (a) Data > Sort > Last Name > Ascending.
This option allows you to navigate to the Data tab in Excel, then select the Sort option. From the sort dialog box, you can choose to sort by Last Name in Ascending order.