单向链表的每一个节点都有一个指向它的后续节点的指针link，现有节点P和q，要将q插入节点p的后面，正确的操作应该是

A．q↑.link: =p↑.link; p↑.link: =q;

B．q: =p↑.link; p↑.link:=q↑.link;

C．q↑.link: =p; p↑.link: =q;

D．q:=p↑.link; p:=q↑.link;