Choose the program with more opportunities which includes great mentorship and research in prospective fields. You have some idea of what you like to do, right? People say, you'll have a complete different idea of what your choices will be after you enter and before you entered. Well, I think the choices weren't really made on substantial thinking/reasoning, just some fantasy. I'm sure one could get a very significant event that changes interest, but that should be a rare instance. You know what you're good at, what you're bad at. Again, things like this may not seem to matter right now, but I think every graduate level decision (ie medical school, dental, PhD, etc) needs to be based on these sorts of things, not rankings. You're pretty much choosing your "major" again. And why is it important to choose earlier? Well, if you know what you want to do, you'll probably seek out steps to reach it faster. The ones who graduated from undergraduate in 3 years knew what major by, the latest, end of the 1st year.
Most of the time, the top ranked schools will seem to have all the leading individuals, but really, no... Of course, the top medical fields are restricted by medical school performance, but this idea should give you some guidance when having to make decisions.
I'm sure just from first judgment, Arkansas will be terrible because...it's Arkansas. And Carver...in Iowa City (Iowa City actually isn't that bad...)? Both of these places are probably associated with corn fields and such. But, it's your training so look deeper... For example, Iowa has pretty strong biophysics research along with strong ophthalmologists... Arkansas has decent cardiovascular clinical research as well as strong pediatric heart surgeons. Read some of the top pertinent journals to stay up to date, including research...for example, Circulation, Science, NEJM Cardiology/Genetics/Surgery. Look at the authors and the corresponding institutions. Look up some people at Arkansas and Iowa. So once you make this decision, you can also factor in life choices, price difference, etc. By this point, price difference will come into perspective.
Once you enter the program, make some proactive moves to seek individuals out and make connections. Then, mentorship could lead to connections or recommendations for your future. And when your recommendations are from the leaders of the field, they'll carry a lot of weight and open up many doors.
Reading and seeking out more about these programs should give a better systematic approach to choosing rather than just going off emotion or some other superficial comparison of the two schools. If you actually think this through with some substantial logical reasons, then you most likely will be "happy," right? Don't just go off of how you felt for that one interview visit. Or what other undergrads think about the program. Go off your own thinking, own research, the ones who've been at the field for a while (but not about to die...). I'm sure you actually looked into the school before you made your decision that you'd apply so all of this thinking you should ultimately narrow down your choice.