尘肺X线胸片上，圆形小阴影大小依据划分为p、q、r三级，如p级为

A.＜1.5mm

B.1.5mm＜B≤3.0mm

C.1.5mm≤C＜3.0mm

D.3.0mm≤D＜1.0mm

E.＜1.5cm