He spoke with Clare,        the telephone rang three times.

A．to which

B．during which

C．on which

D．for which

质量相等的甲、乙两容器放在水平桌面上，两容器内盛有质量相等的水，如图所示．甲、乙容器对桌面的压强分别为P_甲和P_乙，水对两容器底部的压强分别为P_甲′和P_乙′，比较它们压强的大小，正确的是（　　）

A．P_甲＞P_乙，P_甲′＞P_乙′

B．P_甲＞P_乙，P_甲′＜P_乙′

C．P_甲＜P_乙，P_甲′＞P_乙′

D．P_甲＜P_乙，P_甲′＜P_乙′