单项选择题

A.见红、规律宫缩、宫口不开
B.规律宫缩、破膜、胎头下降
C.见红、破膜、规律宫缩
D.规律宫缩,伴胎头下降、宫口扩张
E.见红、规律宫缩、宫口扩张