I 'd rather you ______ about it for the time being. A don't think B didn't think c would not think D had not thought

would rather 后面的宾语从句要用虚拟语气，从句的谓语动词的
形式用法：过去式——表示当时未能实现的愿望/意愿。
过去完成式——表示过去未能完成的愿望/意愿。
过去未来式——表示未来不大可能实现的愿望/意愿。

I 'd rather you ______ about it for the time being. A don't think B didn't think c would not think D had not thought
A选项不符合虚拟语气要求。C是过去未来式，D是过去完成式，都与这个
句子意思不符。
B是过去式，表示当时这个人的意愿没有实现。

所以只有B符合要求。