Complete the partygoer's realization about the lost item.

"This isn't my sparkly scarf. I think it belongs to Sarah. Yes, I'm pretty sure it's ___."

The correct answer is hers.

Hers is a possessive pronoun that stands alone, meaning "her scarf." We cannot use "her" here because "her" is a possessive adjective and needs a noun immediately after it (like "her scarf").