Problem with VB hiding rows

I have created a questionaire where you first select the critera for the questions. The Questionaire Worksheet has a selection of drop down boxes in column D. The Selection Worksheet identifies the what has been selected. The Applicability Workheet determines which questions should be asked.
On the Decisiontree Worksheet I have 3 buttons.
If a number of the questions are answered and the the Show Unanswered questions selected when the SHOW All Questions again it hides the rows that have been answered. I cant work out what Is wrong? This has taken me quite a bit to get to this stage so any help will be greatly appreciated.

Thanks

Since My last post solved my final question from another post.

Thank you very much VBA NOOB. I am so happy now.