The given trinomial can be factored using factorization as
x²+4x-32
=x²+8x-4x-32
=x(x+8)-4(x+8)
=(x+8)(x-4)
Thus x+8 and x-4 are the factors of the given trinomial. From these we can see x-4 is listed in option C.
So the answer to this question is Option C
