First you should include a link to the original question when you say it is a repeat.
But from what you have said it was not actually answered. The link is still desirable though.
Second,
This question seems to require a fair amount of diagram sketching, with thought and considerable time.
Have you done any sketches, have you discounted any of the choices?
Do you think you might have the answer?
I would like to see evidence of your own attempts.