People who drink wine ＿ to drive .为什么不能用isn't allowed
People who drink wine ＿ to drive .
B.isn't allowed
D.mustn't be allowed
【答案是D,我想知道B为什么错了,难道是因为“be allowed to”结构中的be不能够与is are什么的互相转换吗?求学霸解答十分感谢(｡･ω･｡)ﾉ♡√】