<p>Hypothetically, I was accepted to one of UPenn’s dual-degree programs.</p>
<p>If I got accepted in ED, and I decided that the program is not for me, do I have a choice of just picking one college? Does the same go for RD?</p>
<p>Of course you do, but not before matriculation. However, you’d do best to enroll in the program and decide at the end of your freshman or sophomore year 
I guarantee that what you know <em>before</em> coming to college is nothing compared to what you’ll know at the end of a year. Switching (dropping) to a single degree from a joint/dual degree program is just a matter of paperwork. I know a few people who have done it.</p>