With no explanation, label text_A→text_B with either "not_related" or "related".
text_A: Avengers: Age of Ultron is based on American comic books published by Marvel Comics.
text_B: Defensive rating or defensive efficiency is a statistic used in basketball to measure an individual player 's efficiency at preventing the other team from scoring points .. basketball. basketball. It was created by author and statistician Dean Oliver .. Dean Oliver. Dean Oliver ( statistician )
not_related.