单选题：在循环双链表的p所指的结点之前插入s所指结点的操作是（　　）。

在循环双链表的p所指的结点之前插入s所指结点的操作是（　　）。
@[D](2)

A. p->prior = s；
s->next = p；
p->prior->next = s；
s->prior = p->prior
B. p->prior = s；
p->prior->next = s；
s->next = p；
s->prior = p->prior
C. s->next = p；
s->prior = p->prior；
p->prior = s；
p->prior->next = s
D. s->next = p；s->prior = p->prior；p->prior->next = s；p->prior = s



A.p->prior = s；
s->next = p；
p->prior->next = s；
s->prior = p->prior
B.p->prior = s；
p->prior->next = s；
s->next = p；
s->prior = p->prior
C.s->next = p；
s->prior = p->prior；
p->prior = s；
p->prior->next = s
D.s->next = p；s->prior = p->prior；p->prior->next = s；p->prior = s


答案：D