Exam PRINCE2-Practitioner topic 18 question 40 discussion

MANAGING A STAGE BOUNDARY -
During the 'managing a stage boundary' process at the end of stage 2, the project manager is updating the business case and needs to confirm that the aggregated risk exposure for the delivery or the stage a plan remains within the risk tolerances.
Which role should confirm that the risk exposure is acceptable as part of the 'update the business case' activity?