Category = '交通工具'

def __init__(self, color, wheels=4):

self.wheels = wheels

self.color = color

if __name__ == '__main__':

car1 = Car('red')

car2 = Car('brown', 6)

car1.Category = '通信工具'

print(car1.Category)

print(car2.Category)

print(Car.Category)

以上代码的执行结果是（）。