在循环的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;