单项选择题

A.0.5~4.0个抗因子Ⅹa/ml
B.1.5~4.0个抗因子Ⅹa/ml
C.2.5~6.0个抗因子Ⅹa/ml
D.2.5~7.0个抗因子Ⅹa/ml
E.2.5~8.0个抗因子Ⅹa/ml