A & B Entered into an Ante Nuptial Agreement That

A & B entered into an ante nuptial agreement that they would be governed by the conjugal partnership of gains when they will get married. A year thereafter, they got married. Can they change their property relationship during the marriage?

A) They can enter into a contract changing their property relationship and from its perfection, they would be bound by another property regime.
B) They can enter into a contract to change their property regime and it binds them due to the principle of liberty of contracts.
C) They can enter into a contract changing their property regime but must file a petition in court for its approval.
D) They can enter into a contract changing the property relationship and be bound thereby because of the principle of mutuality of contracts.