How an I access the field name section of a field instead of field value for onworkflowproperties?

Question

I have a sequential WF initiated by a list item inofpath form. As of now when I do this this.workflowProperties.Item["JobLocation"].ToString(); it gives me the value in that field. I need Display Name value from that field for my action.

How can get the display name selected? The field is a drop down type binded to a data source.