In this excerpt, the minor character that appears is Ms. Slade's manager. This is because the manager is involved in the events of the story (which makes her a character), but her role is not particularly important, nor is she a developed character, which indicates that she is only a minor character. On the other hand, Ms. Slade is the protagonist, which means that she is the most important character in the story.
The sentence where the predicate nominative is correct is D) The best surfers and Mike and she. Just invert the sentence and you'll know which ones are correct. She and Mike are the best surfers.
