In new temperature scale say 0$\rho$ , the boiling and freezing points of water at one atmosphere are 1000 $\rho$ and 3000 $\rho$ respectively. Correlate this scale with the Centigrade scale. The reading of $0^{0}\rho$ on the Centigrade scale is
(a) 00C (b) 500C
(c) 1000C (d) 1500C