This Extra Field Type is available in Profile Builder Basic or Pro.
You can use this extra field type to allow users to choose data from a predefined list.
You can specify the field title, meta-name to be stored in the database, description, options, labels and default option.
Also, you can set whether this field should be required or not.
This is how it looks like in the front-end.
You can also add an empty first option and give it an appropriate Label. This will allow you to trigger the Required field condition if the user does not select another item.