有以下程序:#include<stdlib.h>struct NODE{ int num;stmct NODE *next;};main(){ struct NODE * p, * q,* r;p=(struct NODE * )malloc(sizeof(struct NODE) );q=(struct NODE * )malloc(sizeof(struct NODE) );r=(struct NODE * )malloc(sizeof(struct NODE) );p->num=10; q->num=20; r->num=30;p->next=q; q->next=r;printf("%d\n",p->num+q->next->num);}程序运行后的输出结果是
A.10
B.20
C.30
D.40