The Construction of a Heat Engine Operating Between Temperatures T₁

The construction of a heat engine operating between temperatures T₁ and T₂,and having an efficiency greater than that of a Carnot engine operating between the same two temperatures,would constitute a violation of

A) the law of the conservation of energy.
B) the first law of thermodynamics.
C) the second law of thermodynamics.
D) Boyle's law.
E) None of these is correct.