Final answer:
The correct statement when using the test data approach is that the 1. test data should include data that the client's system should accept or reject. None of the other statements provided are correct.
Step-by-step explanation:
When using the test data approach, the correct statement is: 1) Test data should include data that the client's system should accept or reject. This is because when testing a client's system, it is important to include data that represents the expected behavior of the system, including both valid and invalid data. This helps to ensure that the system is functioning correctly and can handle different scenarios.
Statement 2 is incorrect because the application programs tested by the auditor's test data should be the same as the ones used by the client throughout the year. This allows for a more accurate representation of the system's performance.
Statement 3 is incorrect because any select data that is used for testing should be properly cleaned up and removed from the client system after testing. This helps to maintain data integrity and avoid any potential issues or confusion.
Therefore, the correct statement is that none of the above statements is correct.