单选题

以下python代码输出为 >>> a=[1,2,3]...

Question

以下python代码输出为

>>> a=[1,2,3]
>>> b=a
>>> b[:] = [x+1 for x in a]
>>> print a, b
>>> b = [x-1 for x in a]
>>> print a, b

A. [2, 3, 4] [2, 3, 4]<br>[2, 3, 4] [1, 2, 3]

B. [1, 2, 3] [2, 3, 4]<br>[1, 2, 3] [1, 2, 3]

C. [2, 3, 4] [2, 3, 4]<br>[1, 2, 3] [1, 2, 3]

D. [1, 2, 3] [2, 3, 4]<br>[1, 2, 3] [2, 3, 4]