The obligation arising from unilateral juridical act shall be subject to the law chosen
by the person who performed the act. From the moment where both parties to such
an obligation are individualised, the choice of law, as well as its alteration or termination shall require the agreement of both parties to this relationship.
2. In the absence of law choice, the unilateral obligation shall be subject to the law of the country in which the person who performed the unilateral juridical act is habitually resident or seated. Where it results from the circumstances that the obligation is more strictly connected with the law of another country, this latter law
shall apply.