An Ideal Heat Engine Can Have an Efficiency of 1 $\degree$

Multiple Choice

An ideal heat engine can have an efficiency of 1 if the temperature of the low temperature reservoir is

A) 0 K.
B) 0 $\degree$ C.
C) 0 $\degree$ F.
D) 0 $\degree$ R.
E) the same as the temperature of the heat source.