my $callback_functions =
    {
    #I am not suggesting this kind of 1,2,3,4 naming convention in your actual code, this is just for demo, it is never a good idea to hard code the index as part of your identifier.
    "question1" => {
                    "answer1" => \&func1,
                    "answer2" => \&func2,
                    "answer3" => \&func3,
                   },
    "question2" => {
                    "answer1" => \&func4,
                    "answer2" => \&func5,
                    "answer3" => \&func6,
                   },
    "question3" => {
                    "answer1" => \&func7,
                    "answer2" => \&func8,
                    "answer3" => \&func9,
                   }
    };