下面代码的执行结果是：ls = ["2020", "20.20", "Python"]ls.append(2020)ls.append([2020, "2020"])print(ls)
选项：

A:['2020', '20.20', 'Python', 2020, ['2020']] ;
B: ['2020', '20.20', 'Python', 2020, 2020, '2020'] ;
C:['2020', '20.20', 'Python', 2020, [2020, '2020']] ;
D:['2020', '20.20', 'Python', 2020]