Which of the following best describes the heat engine?

Question

A. A heat engine works through the conversion of energy in the form of heat to mechanical work.
B. A heat engine works through the conversion of energy in the form of heat to chemical work.
C. A heat engine works through the conversion of energy in the form of cold temperatures to do mechanical work.
D. A heat engine works through the conversion of energy in the form of pressure to mechanical work.

I say b

Answer 1

First sentence.
http://en.wikipedia.org/wiki/Heat_engine

Answer 2

Answer is C

Answer 3

Its B