C. THE CONTEXT CLUES TELL US THAT THE SPEAKER MADE A MISTAKE BY TEL...

2. c. The context clues tell us that the speaker made a mistake by telling Nell about the surprise party.The speaker may be a person who can’t keep secrets (choice a), but the focus in the passage is on theaction (the mistake), not on the person performing the action. Choice b(an idea) doesn’t make sensein the context of the sentence, since we know an action took place, and choice dis similarly incorrect.