在循环双链表的p所指结点之后插入s所指结点的操作是
A.p->next=s; s->pre=p; p->next->pre=s; s->next=p->next;
B.p->next=s; p->next->pre=s; s->pre=p; s->next=p->next;
C.s->pre=p; s->next=p->next; p->next->pre=s; p->next=s;
D.s->pre=p; s->next=p->next; p->next=s; p->next->pre=s;