With no explanation, label text_A→text_B with either "not_related" or "related".
text_A: Karl Urban was in Dredd, Star Trek, and the Riddick series.
text_B: The South Korean clubs in the AFC Champions League .. AFC Champions League. AFC Champions League. This details the participation and performances in the competition since its rebranding and reformatting in 2002 and excludes the details of the old AFC Club Championship .
not_related.