Which of the following sentences contains subjunctive mood？A．Lucy insisted that her son ge

Which of the following sentences contains subjunctive mood？

A．Lucy insisted that her son get home before 5 o"clock.

B．She used to drive to work, but now she takes the city metro.

C．Walk straight ahead, and don"t turn till the second traffic lights.

D．Paul will cancel his flight if he cannot get his visa by Friday.

请帮忙给出正确答案和分析，谢谢！