Synonym of UNTIE

Answer: Option C

Unfold : open or spread out from a folded position.
Unchain : remove the chains fastening or securing (someone or something).
Undo : unfasten, untie, or loosen (something).
Unhinge : make (someone) mentally unbalanced.
Untie : undo or unfasten (something that is tied or tied up).

Synonym of Untie is Undo