Is there still doubt_______ we will get through the task in

Is there still doubt_______ we will get through the task in time? A. that B. whether 我知道英语里有这样两种表达：There is no doubt that...以及There is some doubt whether.但是,主句变成了问句Is there any doubt...时后面的引导词是否要变化?我发现that和whether都在资料上出现过,不知哪一个正确? 我也认为用“that”更好；能说明为什么吗?