With no explanation, label text_A→text_B with either "not_related" or "related".
text_A: Carbon is an element.
text_B: This is a list of those who were granted the rank of Feldmarschall by the Holy Roman Emperor of the Holy Roman Empire of the German Nation , 1618 -- 1806 .. Feldmarschall. Feldmarschall. Holy Roman Emperor. Holy Roman Emperor. Holy Roman Empire of the German Nation. Holy Roman Empire of the German Nation
not_related.