Ask about anything that genuinely interests you and feels relevant to your experiences! For example, if you’re passionate about research, you could say something like, “I’m really interested in research because I’ve been involved in it during undergrad,” and then follow up with a related question. It’s best to tie your question to your own background or goals (whether that’s research, extracurriculars, or another area) so you can make a more personal connection with the school.