The Marines don't allocate the Nrotc mo scholarships according to major like the Navy and Air Force; so a change of major is not going to be an issue. Find a major common to all the schools that are listed on the application. I personally would not put down art as it could make an applicant appear a little flaky to the officers reviewing a scholarship application. The reason I say this is because some of my dad's military colleagues think that the only legitimate majors for their sons in college are engineering, chemistry, physics, math, business, economics, architecture, certain strategic foreign languages, history and political science science. Take a look at the majors offered at the Naval Academy for guidance:
http://www.usna.edu/academics/acmajors.htm
