Any polynomial f(x) will have a root "a" if and only if it satisfy the condition :- f(a)=0 i.e. Factor (x-a) will divide f(x) completely leaving remainder 0.
If we get f(b) = k, where b and k are some integer values. Then 'k' is the remainder after dividing f(x) by (x-b).
Similarly, if we get p(9)=6 for any polynomial p(x). Then we must get 6 as remainder after dividing p(x) by factor (x-9).
Hence, option A is correct i.e. If p(x) is divided by x – 9, the remainder is 6.