Can someone with factoring the trinomial

X^2 - 13x + 40

as you know 40 = 5 x 8 or 40 = (-5) x (-8)
since -13x has -13 as coefficient so they should be (-5) and (-8)

x^2 - 13x + 40 = (x - 5)(x - 8)

(x - 5)(x - 8)
= x ^ 2 - 5x - 8x + 40
x ^ 2 - 13x + 40

so answer
D. (x - 5)(x - 8)