下面程序的运行结果是( )#includevoid main(){ int a,b;for(a=1,b=1;a<=100;a++){ if(b>=20) break;if(b%3==1) {b+=3; continue;}b-=5; }printf("%d\n",a);}

A. 7
B. 8
C. 9
D. 10