The first step we have foolow is to convert mL to L and multiply it by the molarity of the solution:
[tex]275mL\cdot\frac{1L}{1000mL}\cdot\frac{1.2mol}{L}{}=0.33mol[/tex]Use molar mass of NaOH to find the mass of NaOH is:
[tex]0.33mol\cdot\frac{40gNaOH}{mol}=13.33gNaOH[/tex]It means that the correct answer is 13 grams.