A.5.4mg/m3(2ppm) B.13.5mg/m3(5ppm) C.32.5mg/m3(12ppm) D.271mg/m3(100ppm)
A.15mg/m3(10ppm) B.30mg/m3(20ppm) C.75mg/m3(50ppm) D.150mg/m3(100ppm)