Final answer:
Jus ad bellum concerns the justification for entering a war, not the conduct during war, which is governed by jus in Bello. Therefore, the statement in question is false. Therefore, the correct answer is B. False.
Step-by-step explanation:
The term jus ad bellum refers to the set of criteria that are to be consulted before engaging in war, in order to determine whether entering into war is justifiable. This includes various principles, such as having a just cause, being a last resort, and being declared by a proper authority.
Therefore, the statement that 'jus ad bellum refers to rightful conduct during war' is False. The correct term for rightful conduct during war is jus in bello, which governs the behavior of parties engaged in conflict and includes principles such as distinction, proportionality, and military necessity. Therefore, the correct answer is B. False.