单项选择题

A.while(p->next!=NULL)p=p->next;p->next=s;s->next=NULL;
B.while(p!=NULL)p=p->next;p->next=s;s->next=NULL;
C.while(p->next!=NULL)p=p->next;s->next=p;p->next=NULL;
D.while(p!=NULL)p=p->next->next;p->next=s;s->next=p->next;