-What made the student so upset?

-_______ to go to the movie

A．Having not been allowed

B．Not having allowed

C．Because of not having allowed

D．Not having been allowed

队列是一种按"先进先出"原则进行插入和删除操作的数据结构。若初始队列为空，输入序列为abcde，则可得到的输出序列为（）。

A.abcde 

B.abdce 

C.edcba 

D.edabc