For this problem, we need to find an integer for the number of moles of oxygen. Let's see the results by multiplying 2.33 and 2, 3, 4:
[tex]\begin{gathered} 2.33\text{ mol}\cdot2=4.66\text{ moles.} \\ 2.33\text{ mol}\cdot3=6.99\text{ moles}\approx7\text{ moles.} \\ 2.33\text{ mol}\cdot4=9.32\text{ moles.} \end{gathered}[/tex]You can note that if we multiply 2.33 moles by three (3), we obtain an integer of the number of moles.