Griselda Marchbanks had lived for a very long time and was also a senior member of the Wizengamot. In the wizarding world, where the elderly were all the more respected, Professor Marchbanks's connections and influence were hardly inferior to Professor Dumbledore's.
Albert happened to use this exam to verify his identity as a seer.
A seer, or prophet, held an exceptionally high status in the wizarding world. Albert happened to possess this ability, and he also needed the title of seer to boost his reputation, raise his standing in the wizarding community, and reduce any resistance he might encounter in the future.
Chapter 739