The treaty was ratified by the heads of states.

Answer: Option D

Ratified : sign or give formal consent to (a treaty, contract, or agreement), making it officially valid.
Set : put, lay, or stand (something) in a specified place or position.
Unsettled : lacking order or stability.
Destroyed : end the existence of (something) by damaging or attacking it.
Annulled : declare invalid (an official agreement, decision, or result).

Antonym of Ratified is Annulled