25.3 g of sodium carbonate, $\require{mhchem}\ce{Na2CO3}$ is dissolved in enough water to make 250 mL of solution. If sodium carbonate dissociates completely, molar concentration of sodium ion, $\ce{Na+}$ and carbonate ions, $\ce{CO3^2-}$ are respectively (Molar mass of $\ce{Na2CO3}$ = 106 g mol-1)
(a) 0.955 M and 1.910 M
(b) 1.910 M and 0.955 M
(c) 1.90 M and 1.910 M
(d) 0.477 M and 0.477 M