单项选择题

A1/A2型题 第一产程潜伏期是指从()

A.不规律宫缩到宫口开大3cm
B.规律宫缩到宫口开大3cm
C.不规律宫缩到宫口开大2cm
D.规律宫缩到宫口开大2cm
E.规律宫缩到宫口开大5cm