对于句子“通过大量的飞行试验，证明运七飞机具有良好的操作性和可靠的安全性。”的四个英语译文，最佳翻译是

A、Through an extensive flight test, it proves that Y7 aircraft has good controllability and reliable safety. ;

B、By an extensive flight test, it proves that Y7 aircraft has good controllability and reliable safety. ;

C、Repeated flight tests show that Y7 aircraft is of good controllability and reliable safety. ;

D、That Y7 aircraft has good controllability and reliable safety
has been proved by an extensive flight test.