Incremental fuel costs in Rs/MWh for a plant consisting of two generating units are given by\(\frac{{d{F_1}}}{{d{P_1}}} = 0.4{P_1} + 400\;and\frac{{d{F_2}}}{{d{P_2}}} = 0.48{P_2} + 320\)The allocation of loads P1 and P2 between generating units 1 and 2, respectively, for minimum cost of generation to serve a total load of 900 MW, neglecting losses, is

• A. 200 MW and 700 MW
• B. 500 MW and 400 MW
• C. 300 MW and 600 MW
• D. 400 MW and 500 MW