A check

On this lesson, what is the actual function of the explaining step?

It is a reasonable attempt that has not yet been worded well enoughIt hands over material and asks for permission, which keeps the loop turningIt is a sin, because arguing with a parent is forbiddenIt is the only alternative to cutting contact
Not quite

The explaining is not badly worded. It is structurally the wrong move, because it makes the other person the judge of whether you are released, and it supplies material that comes back later. That is not a claim that you may never speak to your parent, and it is certainly not a claim that answering a parent is forbidden. It is a claim about what that particular conversation is doing.