运行下列Python程序后的结果是？（ ）
def f(n): n = n * 2 return n a = [7, 1] b = f(a) print(a, b)
[7,1],[7,1,7,1]
[7,1],[14,2]
[7,1],[7,1],[7,1]
[7,1],[7,1]