The stakeholder formulates the question and knows what to do with the answer.

Everyone in the team is a stakeholder. Literally everyone. Developers are stakeholders. Designers are stakeholders. Managers are stakeholders. The CEO is a stakeholder, too. And so is the board of directors. If someone has a stake in the system, that someone is a stakeholder.

Of course, not everyone will want the same kind of answers, but as long as the questions are about the system, it is the responsibility of the system to provide the information. This responsibility is mediated by the Facilitator.