Steam at 1 Atm and 100 $\degree$ C Enters a Radiator and Leaves as Water (At 1

Multiple Choice

Steam at 1 atm and 100 $\degree$ C enters a radiator and leaves as water (at 1 atm and 80 $\degree$ C) . Take the heat of vaporization to be 540 cal/g. Of the total energy given off as heat, what percent arises from the cooling of the water?

A) 100
B) 54
C) 26
D) 14
E) 3.6