I applied to a graduate program in mathematics at university A. I went to their oral interview, and could not give some proofs that they asked for. As far as I know, university A has two lists: main and reserve. I am not declined, so I think that they put me on their reserve list because there were people who did better than me in the interview. I also applied to university B that I would like to study math at, and did great at their interview.
I'd prefer to choose university A. So, should I pick university A on whose reserve list I am, or university B which put me on their main list?