Sign Computation

Please choose the correct answer by clicking on the letter:

1]       (-3) + 4  =

a]       7                 b]      -7                c]       1                 d]      -1

e]       None of these

2]       -4 - 3 =

a]       7                 b]      -7                c]       1                 d]      -1

e]       None of these

3]       3 - 4 =

a]       7                 b]      -7                c]       1                 d]      -1

e]       None of these