Acknowledge the strongest limitation or risk in your recommendation without abandoning the recommendation itself.

The question is often testing judgment and intellectual flexibility. A strong recommendation does not mean pretending there is no uncertainty. You should be able to explain what could change your conclusion and what you would investigate next.

You might say, 'I would still recommend entering, but the biggest uncertainty is customer adoption. If adoption is materially below our assumption, the economics could change, so I would validate that before committing capital.'

Practice adding one sentence on the biggest risk, one piece of missing information, and what would make you change your recommendation. That gives you a natural way to handle this type of final-round pushback. If useful, this guide on final-round consulting interviews gives more detail.

This sounds like they want you to show the weakness without folding immediately.