A treaty becomes void if its conclusion was procured by the threat or use of force in violation of the principles of the UN Charter. Coercion can be of a state’s representative (Art. 51) or of a state (Art. 52). The use of coercion against the representative of a state for the purposes of procuring the conclusion of a treaty would be a serious matter that is sufficient to declare the treaty devoid of any legal consequence. In practice, sometimes it becomes difficult to make a distinction between the coercion directed at a state or its representative. The correct answer is B.