An Important Feature of the Carnot Cycle Is That

An important feature of the Carnot cycle is that

A) its efficiency depends only on the absolute temperature of the hot reservoir used.
B) its efficiency can be 100%.
C) it is an example of an irreversible process that can be analyzed exactly without approximations.
D) no engine can be more efficient than a Carnot engine operating between the same two temperatures.
E) its efficiency is determined by the temperatures of the hot and cold reservoirs between which it works and by the properties of the working substance used, and on nothing else.