选用罗哌卡因实施可行走的硬膜外分娩镇痛最适宜的浓度是()

A、A．0.15%～0.25%

B、B．0.1%～0.125%

C、C．0.1%～0.2%

D、D．0.075%～0.15%

E、E．0.15%～0.2%