If 5.00cm³ of 0.20 mol dm^-3Na₂CO₃ was diluted with distilled water to obtain 250 cm³ solution, what is the concentration of the resulting solution?

• A 0.004 mol dm^-3
• B 0.02 mol dm^-3
• C 0.20mol dm^-3
• D 0.40mol dm^-3