Final answer:
August initially chooses to be Boba Fett for Halloween, but he changes to a Bleeding Scream costume to match his friend, not any of the options presented in the question.
Step-by-step explanation:
The question refers to August's costume choices in the story. August initially wants to be Boba Fett from 'Star Wars,' but his plans change when his best friend Jack Will decides to go as mummies. August changes his costume from Boba Fett to Bleeding Scream to match with his friend. However, this leads to an insightful part of the story as he overhears a conversation while wearing the Bleeding Scream costume that he wasn't supposed to hear, which gives him an unexpected perspective on his friendships. The correct answer to which costume August ends up wearing is none of the options listed a) through d).