Choose the most appropriate option for blank no. 6

Crater refers to a physical hollow or depression, typically on the surface of the Earth or moon. It is not appropriate in the context of ideological or conceptual differences. While    'division' could work in a general sense, it does not convey the same deep, insurmountable gap as "chasm" does in this context. Fissured is an adjective, not a noun, and does not fit grammatically in this context. The sentence describes a profound and significant gap between different countries' views. "Chasm" (a deep, wide gap or divide) fits best as it conveys the idea of a large and difficult-to-bridge separation in perspectives.