NaOH is an aqueous solution, so one needs to know the concentration of this NaOH (0.1 M, 0.5 M, 1.0 M??) in order to find the moles of NaOH present in 4.5 L. Without that information, we can't answer this question.
Furthermore, the NaOH is a PRODUCT in this reaction, so to state that 4.5 L of NaOH REACTS is incorrect. There are several major problems with this question. Please be sure that you are presenting it EXACTLY as it was given to you.