With no explanation, label text_A→text_B with either "not_related" or "related".
text_A: Grunge became commercially successful in the early 1990s.
text_B: Tegula ignota is a species of sea snail , a marine gastropod mollusk in the family Tegulidae .. species. species. sea snail. sea snail. marine. marine ( ocean ). gastropod. gastropod. mollusk. mollusk. family. family ( biology ). Tegulidae. Tegulidae
not_related.