有以下程序段
int a,b,c;
a = 10;
b = 50;
c = 30;
if(a> b) a = b,b = c;
c = a;
printf("a =%d b =%d c =%d\n ",a,b,c);
程序的输出结果是（ ）
a=10 b=50 c=30
a=10 b=30 c=10
a=10 b=50 c=10
a=50 b=30 c=50