<p>Which program/school would you want to be in if you cannot or do not get accepted by commerce? Go with that.</p>
<p>Many pick Econ as their “back-up” which would be in Arts and Sciences, but others have interests in engineering or architecture, etc.</p>
<p>You can certainly discuss your interests in commerce in the essay, but perhaps include other interests as well? Someone who is (or was) in Comm could probably give you a better answer.</p>