答案选：B
主语是第一人称,且主句谓语是think,believe,expect,suppose,imagine等引导的宾语从句时：
I\We think 仅仅决定反义部分是肯定还是否定,
内容上是对（the party is very good）进行反义提问.
例如：I think the party is very good,isn't he?（I think 是肯定,所以反义部分是否定）
We don't think the party is very good,is it?（We don't think 是否定,所以反义部分是肯定）
但是,当主语不是第一人称时,要对前面提问.
例如：He thinks the party is very good,does't he?
He thinks the party is not very good,doesn't he?