Concept:Irony is a literary device that shows a contrast between what is expected and what actually happens.Explanation:The poem presents death-bringing messengers who carry messages of peace and hope that is hopeless.The oppressor expects that his lies will keep the people calm and subdued.However, those same lies awaken the people's minds and provoke disorder.There is also a contradiction between the expected harm of the “angels of death” and the “messages of peace” they are said to bring.All these situations clearly bring out the use of irony.Answer:B. irony