Drop-down:
This activity is used to choose an option from a drop down/list of choices.

How to use Drop-down activity?
1.    Open a project.
2.    Search for drop down activity and drag and drop it to the workflow.
3.    Double click on the activity and select element.
4.    Hover on the application where you wanted you select the drop-down.
5.    Now, from the drop down select the value and run the workflow.

Technical Reference: