To add brackets to polynomial A-B + C-D, the following addition method is wrong A、(a-b)+(c-d) B、(a+c)-(b+d) C、(a-d)+(b-c) D、 a-(b-c+d)

To add brackets to polynomial A-B + C-D, the following addition method is wrong A、(a-b)+(c-d) B、(a+c)-(b+d) C、(a-d)+(b-c) D、 a-(b-c+d)

C is wrong