Final answer:
The protagonist feeling uneasy best supports the answer.
Step-by-step explanation:
The best detail from the text "someone might be watching" by Shelby Ostergaard that supports the answer to a previous question is B) The protagonist was feeling uneasy. This detail supports the answer because if the protagonist is feeling uneasy, it suggests that there may be a sense of danger or something suspicious happening. This aligns with the idea that someone might be watching, creating a tense and suspenseful atmosphere in the story.