A family of Microsoft presentation graphics products that offer tools for creating presentations and adding graphic effects like multimedia objects and special effects with text.
Your code is very hard to follow!
To add a hyperlink you have to work with a TextRange.
So:
Take the TextRange in the shape, Find the part that is answer18 (which needs to be the link address without http:\) and add the action setting
This should work but I can't see all of the code so some tweaking might be needed
printableSlide.Shapes(2).TextFrame.TextRange.Text = _
answer1 & vbCr & answer2 & vbCr & answer3 & vbCr & answer4 & vbCr & answer5 & vbCr & _
answer6 & vbCr & answer7 & vbCr & answer8 & vbCr & answer9 & vbCr & answer10 & vbCr & answer11 & vbCr & answer12 & _
vbCr & answer13 & vbCr & answer14 & vbCr & answer15 & vbCr & answer16 & vbCr & answer17 & vbCr & answer18
With printableSlide.Shapes(2).TextFrame.TextRange.Find(answer18).ActionSettings(ppMouseClick)
.Action = ppActionHyperlink
.Hyperlink.Address = "http:\" & answer18
End With