Question: Whose responsibility is it to assure that assent has been granted?
Sentence: Independently of the method used to signify royal assent, it is the responsibility of the Clerk of the Parliaments, once the assent has been duly notified to both houses, not only to endorse the act in the name of the monarch with the formal Norman French formula, but to certify that assent has been granted.
Answer in sentence: yes