Which of the following best explains why the term fifty-four forty was related to american expansion in the west?

No statement, let me explain
the term fifty-four forty was related with the American expansion in the area west that included Texas,California and the entire region of Oregon. It's  president Polk, the renowned architect of manifest destiny and American expansion, who coined the slogan. It simply referred to the latitudes of the northern border of Oregon, which was  54-degrees forty minutes.