Below are the choices that can be found elsewhere:
In Grendel, John Gardner uses
first-person point of view to help readers better understand Beowulf’s feelings.
first-person point of view to help readers see Grendel’s side of a familiar story.
third-person point of view to give greater insight into all of the characters.
third-person point of view to give an impartial account of a well-known event.
I think the answer is first-person point of view to help readers see Grendel’s side of a familiar story.