With no explanation, label text_A→text_B with either "not_related" or "related".
text_A: Foo Fighters was motivated by World War II.
text_B: WNCC was a commercial AM radio station , licensed to the Borough of Northern Cambria , Pennsylvania .. AM broadcasting. radio station. radio station. WNCC operated on a federally assigned frequency of 950 kHz with a maximum power output of 500 Watts .. kHz. kilohertz
not_related.