选B mended
It's high time (that) 结构后面接虚拟语态的从句,形式是过去式(如果主语是I 则be动词的形态只能是were)
参考资料,cn.bing.com
high time:正是时候,早该。It's high time that...是应立即做(某事)的时候了,早就到了做什么的时候了。It is (high) time that后面接的从句,谓语动词为:过去式或should+动词原形(should不可省略,虚拟语气)。选B