How do you select 2 schools on the Common App?

I’m really torn between being a biology major and working for a history degree. I’m applying RD rn and I heard I can apply to two of the schools. I’m thinking about applying to CAS first choice and CALS second choice but I can’t figure out how to do it on the common app. Has anyone figured it out?

Some universities allow the two choice. Not Cornell.

Cornell used to allow students to select a first and second choice school, but they discontinued the practice a couple of years ago.