Stuck in the creation of a "link quiz"

Hi everyone!

I'm creating a link quizz like this :

 I have created all the layers to link numbers to letters, and it's work : when you select 1 and A, the corresponding layer appear :

To do this I have created this condition :

So far it's work  :-)

But things get complicated when you continue, for an exemple, if you want to link 2 to B, an other layer 1 to B will appear.

I understand why the layer 1 to B appear, because all the conditions are the same.

So... Do you have an idea on how to make it work?

Thank you for your help, and english is not my mother tongue, so if something seems strange, please let me know :D

You will find the storyline projet in attachment.

Regards
Martin G.