Final answer:
The poem critiquing religious extremism is 'The Second Coming' by William Butler Yeats, depicting the chaos and rising radicalism post-World War I.
Step-by-step explanation:
The poem that serves as a critique of religious extremism is C. "The Second Coming" by William Butler Yeats. This poem uses vivid imagery and powerful language to convey a world turned upside down by the chaos of events post-World War I, hinting at a breakdown of traditional societal and religious structures.
The poem's famous lines "The best lack all conviction, while the worst/Are full of passionate intensity" suggest a lament about the rise of radicalism and the faltering of moderate, compassionate voices.