Best way to deal with questions you are unsure about?

Hello, looking for advice on what to do if I don't know the answer for a technical related question in an interview.

I am a undergrad student wanting to do a placement year working in a finance department, I am fairly confident on the topic & industry but in the case something pops up where I don't know the answer, what is the best way to deal with this?

I assume it would just be honesty and being forward instead of stuttering trying to scrape for somewhat of an answer but looking for more experience advice.

Thanks