题目内容：

She said that her mother ( ) for three years.A.has been dead B.has died C.had been dead D,had die

优质解答

C.had been dead
句子的开始She said that已经是过去时态了,根据句意,从句也应该是过去时态,排除了A和B,选项D had die的形式错误,所以选C.