2.Perform operation test of TCAS by resetting circuit breaker of TCAS.a) Reset the circuit breaker of TCAS so that the operation of TACS works.b) The way to do the TACS operation test is to reset the TCAS circuit breaker.c） Do an operational test t

2.Perform operation test of TCAS by resetting circuit breaker of TCAS.a) Reset the circuit breaker of TCAS so that the operation of TACS works.b) The way to do the TACS operation test is to reset the TCAS circuit breaker.c） Do an operational test t
2.Perform operation test of TCAS by resetting circuit breaker of TCAS.
a) Reset the circuit breaker of TCAS so that the operation of TACS works.
b) The way to do the TACS operation test is to reset the TCAS circuit breaker.
c） Do an operational test to make sure that the TCAS works ok.

2.Perform operation test of TCAS by resetting circuit breaker of TCAS.a) Reset the circuit breaker of TCAS so that the operation of TACS works.b) The way to do the TACS operation test is to reset the TCAS circuit breaker.c） Do an operational test t
选B,原句：执行TCAS的操作考试通过重新设置TCAS的断路器.主要考BY的意思,是途径,不是结果.

b的意思跟原句相同，选b，望采纳

选b）。这个无甚疑问，主要是理解了 by的意思就可以了，在这里是 通过... 之意，这样逻辑关系就通了。