【单选题】

When there is an ""emergency"" situation, it is usually a failure that requires an immediate and quick response, such as an entire engine failure, fire or smoke, or perhaps a rapid drop in cabin pressurE."

A、For "emergency", the related failure should be responded immediately, for example, the total engine failure, fire or smoke, sudden cabin pressure lost.
B、An "Emergency" almost including a serious failure that requires later response, such as a total engines failure, flame out or smoke, or rapid cabin pressurization.
C、For "emergency", the related failure should be treated immediately, for example, the total engine is not malfunctioning, fire or smoke, sudden cabin pressure lost.