Need Help Creating a DropDown List that Dictates the DropDock Options for Another List

I am well aware of how to create a drop-down data validation list; however, I am facing challenges with creating a drop-down list that only displays relevent options from another drop-down list. For example: there are 4 total options for each selection (yes, no, often, and infrequently) but some of the selections only have 2 relevent options (yes, no).

I am trying to display a drop-down list that once the selection is chosen, only the relevent options will appear in drop-down list #2. Thanks.

-Jordan

http://easy-excel.com/dynamic-drop-down-in-excel/