Use the process of elimination.
There is a positive b value and a negative c value, which means that there is a negative factor and positive factor. This eliminates A and C.
Multiply out the factors in B and D:
B
(6d - 1)(2d + 1)
6d * 2d = 12d^2
6d * 1 = 6d
2d * -1 = -2d
12d^2 + 4d - 1
D
(6d + 1)(2d - 1)
6d * 2d = 12d^2
6d * -1 = -6d
2d * 1 = 2d
12d^2 - 4d - 1
The answer is B.
