An Electrical Generating Plant Operates at a Boiler Temperature of 220

An electrical generating plant operates at a boiler temperature of 220 $\degree$ C and exhausts the unused heat into a nearby river at 19 $\degree$ C.If the generating plant has a power output of 800 megawatts (MW) and if the actual efficiency is 3/4 the theoretical efficiency,how much heat per second must be delivered to the boiler? (0 $\degree$ C = 273 K)

A) 5 200 MW
B) 1 810 MW
C) 3 620 MW
D) 2 620 MW