Senior candidates list options: "We could use MySQL or PostgreSQL or MongoDB."
Staff candidates make decisions: "I recommend PostgreSQL because we need complex queries with transactions, and our team already has PostgreSQL expertise."
Always state your recommendation first, then justify it. If the interviewer disagrees, they'll push back. That's good. It starts a technical discussion where you can show reasoning.
The worst answer is "it depends" without a follow-up decision. Make a call. Defend it.