Let's look at these terms. "Vetoing" means DENYING--the OPPOSITE of approval! (A is wrong.) "Impeachment" is a term used when an official is accused of breaking the law, this has nothing to do with approving the Constitution. (C is wrong.) "Levying" is when you put a new tax in effect--again, not related. (D is wrong.)
Ratification is an official method of approval for laws and documents. B is correct!
Answer: B. ratification