With no explanation, label text_A→text_B with either "not_related" or "related".
text_A: Boeing 737s serve markets previously filled by 727 airliners.
text_B: Auto Research Center , also known as ARC Indy , is a research and development company with headquarters in Indianapolis , Indiana USA .. Indianapolis. Indianapolis. Indiana. Indiana. It was founded as Reynard Motorsports North American headquarters , and became its own company in 2002 .. Reynard Motorsports. Reynard Motorsports
not_related.