First, it's good to know that the factored form of a quadratic can give you the roots of the graph it matches with. This can be done by handling each bracket individually; let's use (x+3) and (x-5) for example. (x+3)(x-5)=0, so x+3=0 ∴ x=-3, and x-5=0 ∴ x=5
Knowing that, take a look at the graph's roots. They are (1,0) and (8,0). This means that the numbers in the brackets will be the opposite value of x for each coordinate. Therefore (x-1)(x-8), A, is your answer.