The PRINCIPLE OF DISTINCTION in international humanitarian law (Article 48 AP I) requires parties to a conflict to:

1. Article 48 of Additional Protocol I 1977 to the Geneva Conventions (Basic rule): 'In order to ensure respect for and protection of the civilian population and civilian objects, the Parties to the conflict shall at all times DISTINGUISH between the civilian population and combatants and between civilian objects and military objectives and accordingly shall direct their operations only against military objectives.' 2. This codifies the PRINCIPLE OF DISTINCTION — a cornerstone of IHL. 3. Closely related: principle of proportionality (Article 51(5)(b) AP I); principle of military necessity; principle of humanity. 4. Violation of distinction is a war crime under the Rome Statute (Article 8(2)(b)(i)). 5. Hence option B is correct. _Source: UN Charter 1945 / Vienna Convention on Law of Treaties 1969 / Geneva Conventions 1949 / ICJ Statute / UDHR ICCPR ICESCR — Additional Protocol I 1977, Article 48 (Basic rule); Customary IHL Rule 1_