Three Carnot Engines Operate Between Temperature Reservoirs as Follows: Engine

Multiple Choice

Three Carnot engines operate between temperature reservoirs as follows: Engine A: T_h = 1 100 K,T_c = 1 000 K;Engine B: T_h = 550 K,T_c = 500 K;Engine C: T_h = 1100 K,T_c = 500 K.Which two engines have the same thermal efficiency?​

A) A and C
B) B and C
C) A and B
D) No two have the same thermal efficiency.
E) ​A and B and C