有以下程序 struct STU { char num[10]; float score[3]; }; main() { struct STU s[3]={{"20021",90,95,85}, {"20022",95,80,75}, {"20023",100,95,90}},*p=s; int i; float sum=0; for(i-0;i＜3,i++) sum=sum+p-＞score[i]; printf("%6.2f/n",sum}; } 程序运行后的输出结果是

A．260

B．270

C．280

D．285