Final answer:
The statement is false as all reversible engines operating between the same two reservoirs can have the same maximum efficiency as the Carnot engine, but not all heat engines are necessarily reversible or have the same efficiency. So, the correct option is B.
Step-by-step explanation:
The statement in the question is false. Carnot's Principle as stated by the second law of thermodynamics specifies that no heat engine can be more efficient than a Carnot engine operating between the same two reservoirs. However, this does not mean that all heat engines have the same efficiency. It specifies that all reversible engines would have the same maximum efficiency as a Carnot engine when they are operating between the same two reservoirs. Real engines (irreversible) are less efficient than reversible engines. Therefore, a Stirling engine, or any other heat engine, cannot surpass the efficiency of the Carnot engine within the same two heat reservoirs, and often they have lower efficiencies.