以下四个选项中的程序片段，输出结果不同于其它三项的是（ ）。
int a = 3, b = 6; int c = a * b / 2; cout << c;
int a = 3, b = 6; int c = 3 + 6; cout << c;
int a = 3, b = 6; int c = a * a / b * b + b; cout << c;
int a = 3, b = 6; int c = b * b / a - a; cout << c;
