下面哪个代码可以创建一个名为cat的实例，属于Animal类，有color和sound两个属性，分别赋值为"black"和"meow"？（ ）
cat = Animal()
cat = Animal()
cat.color = "black"
cat.sound = "meow"
cat.color = "black"
cat.sound = "meow"
cat = Animal()
cat = new Animal()
cat.color = "black"
cat.sound = "meow"
