Identify the pivot positions in the original matrix. The pivot positions are indicated by bold values. Choose the correct answer below.

A.
1 2 3 4
3 4 5 6
5 6 7 8
B.
1 2 3 4
3 4 5 6
5 6 7 8
C.
1 2 3 4
3 4 5 6
5 6 7 8
D.
1 2 3 4
3 4 5 6
5 6 7 8