Locking fields based on radio button

[Proprius]

Here is my setup. I have a set of radio buttons with Case A, Case B, and Case C. If Case A is selected, I would like another set of radio buttons to become editable. If Case B, I would like a text field to become editable. Otherwise, the second set of radio buttons and text field should not be able to be edited, and preferably grayed out if possible.

What's the best way to do this? Thanks!

[mr_vodka]

Do a search for +Visibility and you should come across some examples that should get you started.