The polynomial 24x3 − 54x2 + 44x − 99 is factored by grouping.

24x3 − 54x2 + 44x − 99

24x3 + 44x − 54x2 − 99

4x(____) − 9(____)

What is the common factor that is missing from both sets of parentheses?

6x + 11
6x − 11
6x2 + 11
6x2 − 11