If you genuinely blank, do not fill the silence with random words. Tell the interviewer you want a moment to think, then return to the objective and build a simple starting point.

Ask yourself what the question requires, what information you have, and what two or three logical possibilities exist. Even a basic structure is better than panicked improvisation.

If you are still stuck, asking for clarification or a small prompt is better than remaining frozen. Recovery and composure are part of the evaluation. If useful, this guide on structured communication in case interviews gives more detail.