If 50 mL of 0.5 M oxalic acid is required to neutralize ₂5 mL of NaOH solution, the amount of NaOH in 50 mL of the given NaOH solution is:
a) 0.₁ moles
b) 0.₂ moles
c) 0.3 moles
d) 0.4 moles