what is the factored form of x^2 - 196 ?
A(x-14)^2
B(x+14)^2
C(x - 28)(4x+7)
D(x-14)(x+14)
A(x-14)^2
B(x+14)^2
C(x - 28)(4x+7)
D(x-14)(x+14)