Use the grouping method to factor the polynomial below completely.
3x3 + 9x2 + 5x + 15
O A. (3x2 + 3)(x+5)
O B. (3x2 + 5)(x + 5)
O C. (3x2 + 3)(x+3)
O D. (3x2 + 5)(x + 3)