O young Lochinvar is come out of the west, Through all the wide Border his steed was the best.
6 is CORRECT.
Every schoolboy in the Ireland of my youth had to memorize this rousing poem by Sir Walter Scott. The galloping rhythm can be fun to read aloud. The line has four anapests with a missing first unstressed syllable("[-] oh YOUNG | loch in VAR | is come OUT | of the WEST")