Answer:
a. the creature’s actions
Step-by-step explanation:
In the excerpt from the novel "Grendel," the author John Gardner directs attention to the Grendel's actions to reveal the protagonist's characterization. Actually, he mentions how at the sight of Hrothgar's kingdom the creature moves his hands and mouth to scream, and then runs away to the lake.
The rest of the options are incorrect because in the excert the author does not mention neither Grendel's thoughts nor Beowulf's words or viewpoint.