The given trinomial can be factored using factorization as
x²+6x+8
=x²+2x+4x+8
=x(x+2)+4(x+2)
=(x+2)(x+4)
Thus x+2 and x+4 are the factors of the given trinomial. From these we can see x+4 is listed in option B.
So the answer to this question is Option B