How many of the following polymers contain 1, 3-butadiene as one of the monomer? Butyl rubber, nitrile rubber, ABS plastic, SBR, GRA, natural rubber, neoprene

Butyl rubber (a polymer of buta-1,3-diene) Nitrile rubber (a polymer of acrylonitrile and buta-1,3-diene) ABS plastic (a polymer of acrylonitrile, buta-1,3-diene and styrene) SBR (a polymer of styrene and buta -1,3-diene) GRA (or buna-N) (a polymer of buta-1,3-diene and acrylonitrile) Natural rubber (a polymer of 2-methylbuta-1,3-diene) Neoprene (a polymer of 2-chlorobuta-1,3-diene)