In the past 3 years, six W66 passenger planes have crashed. In the face of the tragic scenes, people could not help but suspect the design of the W66 passenger plane. The manufacturer countered that each accident investigation showed that the responsibility of the accident was the driver Operation error. Which of the following premise is the above manufacturer's words based on? ["The design of A. W66 is not the cause of the pilot's mistake, which will cause the plane to crash.", 'An aircraft crash caused by a design error can be distinguished from an aircraft crash caused by a manufacturing defect.', 'People who suspect that there is a problem with the W66 design have not identified any design issues.', 'For W66 type aircraft, the accident rate of 6 crashes every 3 years is not high.']