There are an infinite number of expressions that are equivalent to it. A few of them are:
-- 3(2x + x + 3)
-- (9x + 9)
-- 3(3x + 3)
-- 9(x + 1)
-- (18x + 18) / 2
-- 3√(x² + 6x + 9)
Without seeing the list of choices that you neglected to post along with the rest of the question, it's not possible for us to guide you to the correct choice.
