单项选择题

A.SS:50mg/L,CODCr:200mg/L,BOD5:50mg/L
B.SS:40mg/L,CODCr:300mg/L,BOD5:20mg/L
C.SS:30mg/L,CODCr:100mg/L,BOD5:30mg/L
D.SS:30mg/L,CODCr:100mg/L,BOD5:50mg/L