Conditional Formatting - End Form based on answer

It seems like forms were able to be terminated based on an answer but I can no longer find that option. Is there still a way to accomplish this?

Thanks!

I am not exactly sure what are you trying to achieve. 

You can hide/show the form fields based on an answer. If the answer is not correct you can hide all form fields and the user will not be able to submit the form. Or you can show other fields if an answer is correct.

How to Show or Hide Fields Base on User's Answer

Hide or Show Multiple Fields at Once

If I did not understand your question correctly, please explain in more details what are you trying to achieve. If you have an old form where you were able to "terminate it" based on an answer, please provide us an ID of that form.