The given trinomial can be factored using factorization as
x²-13x+36
=x²-9x-4x+36
=x(x-9)-4(x-9)
=(x-4)(x-9)
Thus x-4 and x-9 are the factors of the given trinomial. From these we can see x-9 is listed in option C.
So the answer to this question is Option C