A Steam Engine Is Operating at Its Theoretical Maximum Efficiency $\degree$

Multiple Choice

A steam engine is operating at its theoretical maximum efficiency of 60%. If the waste heat has a temperature of 38 $\degree$ C, what is the temperature of the boiler?

A) 350 $\degree$ C
B) 94 $\degree$ C
C) 225 $\degree$ C
D) 504 $\degree$ C
E) 775 $\degree$ C