In this respiratory experiment, which of the following is correct ( )<br/> A、Anesthesia, vagus nerve separation, endotracheal intubation, and respiratory transducer<br/> B、Anesthesia, vagus nerve separation, respiratory transducer and endotracheal intubation<br/> C、Anesthesia, endotracheal intubation, vagus nerve separation, and respiratory transducer attachment<br/> D、Anesthesia, endotracheal intubation, and respiratory transducer, vagus nerve separation