Welcome to the forum @andreawwenyi ,
Could you see if this solution here would work for you?
Let me know if you need help adapting it to your use case!
As for modifying the available options set based on user answers:
There are two challenges related to it: 1) you might quickly end up with an unmanageable list of options due to coders introducing too many variations (even spelling mistakes) 2) since the mechanism of building the task is a function shared by all annotators one annotator's additions would affect what other annotators see unless you keep their sessions completely independent which would require a custom session factory and splitting tasks between the annotators upfront rather than using the Prodigy task router.