Plz help for 100 points

Let the closed interval [a , b] be the domain of function f. the domain of f(x - 3) is given by (a) the open interval (a , b) (b) the closed interval [a , b] (c) the closed interval [a - 3 , b - 3] (d) the closed interval [a + 3 , b + 3]

The sum of these consecutive integers is equal to 9 less than 4 times the least of the integer. find the three integers

The anwser cause i do not understand just plez