单项选择题

A.a1-2<0.1MPa-1、0.1MPa-1≤a1-2<0.5MPa-1、a1-2≥0.5MPa-1
B.a1-2≥0.5MPa-1、0.1MPa-11≤a1-2<0.5MPa-1、a1-2<0.1MPa-1
C.a1-2<0.5MPa-1、0.5MPa-1≤a1-2<1.0MPa-1、a1-2≥1.0MPa-1
D.a1-2≥1.0MPa-1、0.5MPa-1≤a1-2<1.0MPa-1、a1-2<0.5MPa-1