Cant escape # by using \ in a Cloze question

I want music students to identify notes in a musical scale with a CLOZE question type.
Example: Question should read: What are the notes in a D major scale? Answer should read: D E F# G A B C# D but instead reads D E F G A B C D. I tried using a double
and this worked sometimes but was only good for one edit (it seems each time the question was updated, one \ was removed. Very often, the question would not update at all with messages " could not update question" and "could not insert new question"

Code I write is is attatched.