In the fire code, ABS plastics are designated as ___ plastic materials.

IFC Section 2303.7 classifies ABS (acrylonitrile butadiene styrene) plastics as Group A (high-hazard) due to their flammability and smoke production, per NFPA 13. Options B and C are less hazardous, D is a commodity class, not a plastic group. Thus, A is correct.