有一室间隔缺损患儿，用连续多普勒测定其穿隔分流速度为4m/s，肺动脉前向血流速度为5m/s，肱动脉收缩压为96mmHg。该患儿左心室与右心室间的收缩期压差大约是

A.16mmHg

B.32mmHg

C.64mmHg

D.74mmHg

E.90mmHg