双链表的每个结点包括两个指针域。其中rlink指向结点的后继,llink指向结点的前驱。如果要在p所指结点后插入q所指的新结点,下面哪一个操作序列是正确的
A.p↑.rlink↑.llink:=q; p↑.rlink:=q; q↑.llink:=p; q↑.rlink:=p↑.rlink;
B.p↑.llink↑.rlink:=q; p↑.llink:=q; q↑.rlink:=p; q↑.llink:=p↑.llink;
C.q↑.llink:=p; q↑.rlink:=p↑.rlink; p↑.rlink↑.llink:=q;p↑.rlink:=q↑;
D.q↑.rlink:=p; q↑.llink:=p↑.llink; p↑.llink↑.rlink:=q;p↑.llink:=q;